If you're here, I hope you're all about tasteful unique cars which I will help you to create and give a lot examples of. Let's go.

To get your personal colors, you need a crew on social club. Some random won't work because you need to have full access to crew management. If you still don't have one, it's time you create it. Creation will not be covered here because it is easy and it won't take you long to figure out how to do it (or use youtube).

Once you have your crew ready, continue to next step.

This part might sound easy, but it's trickier than you think.
GTA renders colors differently, distorting them to be more pale and brighter than in html codes. That can be quickly fixed, obviously enough, by making the color darker and giving it more value.

On this example, I'll be using '56 Ford Thunderbird in Sunset Coral. Google images is a great place for references, and that's what I'm using. Ideally, you want a photo at daylight, no clouds and shadows. Also, photos may vary because of editing, different cameras, etc. But find what suits you the best.
Here's what I got
 


Now onto sampling. Here's the Site [html-color-codes.info] I use to get colors from images. But you also need to know where to pick the color from as it changes quite a lot on the image itself.
You want a place without reflections (or with those that reflect dark objects, such as asphalt) and under light (but not too much). The image below shows where I could pick from my image.
 


I did that and got #F1A4B8. It appears very pale in game, and little brighter than I want it to be, so I move the slider to the bottom and to the right. Which gives me the color you see on image.
 


Here's my rule of thumb for color palette by "zones"

• 1 - greyscale or nearly black colors
  
• 2 - REALLY pale colors
  
• 3 - why would you be here (works only for blueish grey)
  
• 4 - soft pastel colors
  
• 5 - deep colors that can look quite stunning if you're on the right
  
• 6 - common colors
  
• 7 - you must not be here

 

And there's the end result, slightly customized.
 

Looks hard and scary, but the whole process takes less than a minute once you get hand of it.

• Go to your crew management, Edit crew
  
• Find the box for colors, RMB on it
  
• Select inspect element and console will pop up.

• You will have a window like that or similar (I used Firefox browser here)
  
• Look for 2 marked areas, there should already be your previous color there
  
• Change those hexes, close the console and Save the crew
  
• If you done it right, you'll have a blank/checkered box like on previous image.

Social club doesn't accept 6-digit codes. Fix this by adding one of following suffixes to the hex like on the image below: FF, AA, 00, 55, any other doubled 0-9, A-F (these 4 tend to work in 99% cases)

Now you got your custom hex, time to do some more magic. Using one harmless glitch that will get you banned within minutes of using it you can set your color's base to one of 9 available in game:

• Utility
  
• "Dull" Classic
  
• Classic
  
• Epsilon
  
• Brushed metal
  
• Brushed gold
  
• Pure gold
  
• Matte
  
• Worn (unpurchasable)

Detailed info on each can be found below.
chrome has big gei and is for ricers ok

I used Worn Green Gresley I found on the street just before taking screenshots and was going to keep Worn base.

If the car has 2 colors you need to do this entire procedure twice, for primary and 2ndary. separately. And if you don't know yet, you can't have 2 different custom hexes for primary and 2ndary.

Here's how you do it:

If you already have the base you need, skip first 2 steps.

1 Drive into LSC, buy the color with the base you want.
2. Back out of customs, wait 10-15 secs for color to be saved.

3. Drive into LSC, buy your crew color
 
At this point you won't see the base you selected.
 

4. Exit LSC and go back to single player, the quicker the better
 

5. Go back online, and your car will be ready and waiting for you with new base and paint

These are well-known and used more often, but since we have a painting guide here, why not include them too.

1. Enter LSC and head to Respray
   
2. Open Metallic category, scroll through a few colors
   
3. Leave Respray and open Plates
   
4. Buy a different plate (your personal free plate won't work) and change back to stock
   
5. Open Respray and there you'll have pearlscents available as if the color is metallic

Note that it won't work on wheels that have even small parts (such as outline) of chrome or metal.

1. Enter LSC and put any wheels you want, doesn't matter
   
2. Paint them the color you want
   
3. Revert back to stock wheels
   
4. Exit LSC and leave to single player
   
5. Once you get back online, you'll see the wheels with the paint you've set before.

 

A really plain, non-reflective base. Used to make the car look like a daily driver that doesn't get washed and waxed often
Can be obtained on any car simply by purchasing crew color and NOT doing the glitch (just put the resprayed car back into garage)

 

Really similar to Utility, but slightly less reflective, has the same purpose. Boring too.
Obtainable with following LSC colors:
Black, Carbon Black, Midnight Wine, Midnight Blue, Midnight Purple.

 

Standard-issue base
Found on any LSC classic/metallic color except those with "dull" or Epsilon base.

 

Shinier and clearer version of classic, difference becomes very noticable at <10% brightness hexes, nevertheless can be a cheap little gimmick on any paint. Best for waxed show car look.
Can be purchased with Ice White and Diamond Blue.

 

A very metall-ish paint, it's quite bad on bottom 40% of color table as it "removes" the color under light leaving bare metal look.
Purchasable with Brushed Steel, Brushed Dark Steel and Brushed Aluminium.

 

Similar to Brushed metal, but has a lower brightness threshold for absorbing the color. Also looks less like metal with brighter colors.
Can be bought only with Brushed gold.

 

Epsilon of metals, most reflective and the brightest. Doesn't look dook with dark hexes too.
Can only be purchased with Pure gold.

Your normal matte paint, nothing special. Also the best option for rusty liveries unless Worn is available.
Can be found on any matte color.

 

Many will mistake it for matte because they've never heard of it, but it's quite different. Doesn't have that matte feel and in fact closer to Util rather than it. Also has white reflections that are completly different from white pearl.
Unpurchasable, but can be found on street cars, list below.

Those previews above were done on dark water-blue color #082b3f and might not be enough for you to see distinction between metal and classic colors, so here're some more with different hexes.

Brushed metal - Brushed gold - Pure gold with #aa5bba
 



"Dull" classic - Util - Classic - Epsilon with pure black

This is the list of cars with Worn base (both colors or only primary) that you can steal from streets and repaint to your needs.

Buccaneer - Dark Green primary, Matte Lime Green pearl[imgur.com],
upgraded to lowrider [i.imgur.com]
Buccaneer - Baby Blue [i.imgur.com], upgraded to lowrider[prod.hosted.cloud.rockstargames.com]
Peyote - Dark Red[imgur.com]
Sandking - Baby Blue [i.imgur.com]
Sabre Turbo - Seawash primary[i.imgur.com],
upgraded to lowrider [i.imgsafe.org]
Buffalo - Taxi Yellow primary and pearl [i.imgur.com]
Domintator - Orange2 primary and pearl [i.imgur.com]
F620 - Shadow Silver [i.imgur.com]
Felon GT - Silver Gray [i.imgur.com]
Granger - Straw Beige [i.imgur.com]
Gresley - Dark Green, Worn Green pearl [i.imgur.com],
Manana - Black [imgur.com]
Mesa - Silver Gray [i.imgur.com]
Rumpo - Shadow Silver [i.imgur.com]
Sadler - Blue Silver [i.imgur.com]
Seminole - Honey Beige [i.imgur.com]
Sanchez - Worn Olive Army Green[i.imgur.com]


Also, ALL rusty vehicles that you see spawning on streets have Worn base. So if you're going for classic look on your upgraded Voodoo [i.imgur.com] or Tornado [i.imgur.com], definetly steal them in rusty condition.

Continuation of full-Worn painted cars, a long list of unusual things that can be found from street and stored in your garage. Each link contains a preview of an unmodified street car. Cars that have 2 variants like Zion (+ cabrio) and Sentinel (+ XS) have the same colors.
Pearlscents can be kept if you apply a crew color right over the stock color. To get metallic base can be kept by doing the glitch listed above.

Felon - Util Silver pearl[i.imgur.com]
Felon GT - Brushed Aluminium pearl[i.imgur.com] compared to Bluish Silver[i.imgur.com]
Oracle XS - Util SeaFoam Blue pearl[i.imgur.com]
Oracle XS - Champagne primary[i.imgur.com]
Sentinel - Util Blue pearl[i.imgur.com]
Sentinel - Worn Silver Grey secondary[i.imgur.com]
Sentinel - Worn Golden Red secondary[i.imgur.com]
Sentinel - Util Maui Blue Poly pearl[i.imgur.com]
Sentinel - Util Garnet Red secondary[i.imgur.com]
Sentinel - Util Silver pearl[i.imgur.com]
Zion - Worn Silver pearl[i.imgur.com]
Zion - Matte Orange pearl[i.imgur.com]
Zion - Champagne primary and secondary[i.imgur.com]

Dilettante - Util Blue pearl[i.imgur.com]
Dilettante - Champagne primary and pearl[i.imgur.com]
Issy - Champagne primary[i.imgur.com]
Prarie - Util Dark Green primary and pearl[i.imgur.com]

Buccaneer - Util Garnet Red primary and pearl [i.imgur.com]
Buccaneer - Champagne pearl[i.imgur.com]
Dominator - Champagne pearl[i.imgur.com]
Dominator - Matte Orange pearl[i.imgur.com]
Gauntlet - Worn Black secondary[i.imgur.com]
Gauntlet - Matte Orange pearl[i.imgur.com], another variant[i.imgur.com]
Phoenix - Worn Dark Red secondary and pearl[i.imgur.com]
Phoenix - Util Dark Green primary and secondary, Util Green pearl[i.imgur.com]
Phoenix - Util Midnight Blue secondary[i.imgur.com]
Phoenix - Util Light Brown pearl[i.imgur.com]
Ruiner - Worn White pearl[i.imgur.com]
Ruiner - Util Dark Green primary[i.imgur.com]
Ruiner - Util SeaFoam Blue pearl[imgur.com]
Sabre Turbo - Util Bright Red pearl[i.imgur.com]

Rancher - Champagne primary[i.imgur.com], another variant[imgur.com]
Rancher - Util Gun Metal pearl[i.imgur.com]
Sandking - Util Silver pearl[i.imgur.com], 2nd variant[i.imgur.com], 3rd variant[i.imgur.com], 4th variant[i.imgur.com]
Sandking - Util Dark Silver pearl[i.imgur.com]

Emperor - Util Gun Metal pearl[i.imgur.com]
Emperor - Util Dark Green primary[i.imgur.com]
Emperor - Util Blue primary[i.imgur.com]
Fugitive - Worn White pearl[i.imgur.com]
Ingot - Util Dark Green pearl[i.imgur.com]
Ingot - Champagne pearl[i.imgur.com]
Ingot - Matte Gray pearl[i.imgur.com]
Ingot - Util Maui Blue Poly pearl[i.imgur.com]
Primo - Util Medium Brown secondary[i.imgur.com]
Primo - Champagne pearl[i.imgur.com]
Schafter - Worn Silver pearl[i.imgur.com]
Schafter - Matte Orange pearl[i.imgur.com]
Schafter - Champagne primary and secondary[i.imgur.com]
Stainer - Worn Silver pearl[i.imgur.com]
Stainer - Champagne primary[i.imgur.com]
Stratum - Util Silver pearl[imgur.com]
Stratum - Util Dark Blue pearl[i.imgur.com]
Surge - Worn White pearl[i.imgur.com]
Washington - Util Blue pearl[i.imgur.com]
Washington - Util Maui Blue Poly pearl[i.imgur.com]
Washington - Util Silver pearl[i.imgur.com]

Buffalo - Champagne primary and pearl[i.imgur.com]
Futo - Worn Shadow Silver pearl[i.imgur.com], another variant[i.imgur.com]
Futo - Champagne primary[i.imgur.com]
Penumbra - Util SeaFoam Blue pearl[i.imgur.com]
Penumbra - Champagne primary[i.imgur.com]
Schwartzer - Worn Silver pearl[i.imgur.com]
Schwartzer - Champagne primary[i.imgur.com]

Baller - Matte Grey pearl[i.imgur.com]
Baller - Worn Green pearl[i.imgur.com]
Beejay - Util Green pearl[i.imgur.com]
Beejay - Util Light Brown pearl[i.imgur.com]
Dubsta - Util SIlver pearl[i.imgur.com]
Dubsta - Worn SeaWash pearl[i.imgur.com]
Dubsta - Util SeaFoam Blue pearl[i.imgur.com]
FQ2 - Util Seafoam Blue pearl[i.imgur.com]
FQ2 - Util Medium Brown pearl[i.imgur.com]
Gresley - Util Seafoam Blue pearl[i.imgur.com]
Habanero - Util Silver pearl[i.imgur.com]
Habanero - Worn Silver Grey pearl[i.imgur.com]
Habanero - Matte Orange pearl[i.imgur.com]
Habanero - Worn Blue pearl[i.imgur.com]
Mesa - Champagne primary[imgur.com]
Mesa - Worn SeaWash pearl[i.imgur.com]
Mesa - Worn Honey Beige pearl[i.imgur.com]
Patriot - Champagne pearl[i.imgur.com]
Radius - Util Bright Red pearl[i.imgur.com]
Radius - Worn Blue pearl[i.imgur.com]
Radius - Util Blue pearl[i.imgur.com]
Radius - Util SeaFoam Blue pearl[i.imgur.com]
Radius - Util Silver pearl[i.imgur.com]
Seminole - Worn Dark Green secondary[i.imgur.com]
Seminole - Util Silver pearl[i.imgur.com]
Serrano - Util Bright Red pearl[i.imgur.com]
Serrano - Worn Silver Grey pearl[i.imgur.com]

Reached character limit by adding hell lot of links there

Sadler - Util Garnet Red pearl[i.imgur.com]
Sadler - Worn Green pearl[imgur.com]
Sadler - Util Midnight Blue primary, Util Blue pearl[i.imgur.com]
Sadler - Matte Light Gray pearl[i.imgur.com]
Sadler - Util Silver primary[i.imgur.com]
Sadler - Worn Blue Silver[i.imgur.com]

Bison - Matte Red pearl[i.imgur.com]
Bison - Worn Shadow Silver pearl[i.imgur.com]
Bobcat - Worn Honey Beige secondary[i.imgur.com]
Bobcat - Util Blue everything[i.imgur.com]
Speedo - Util Light Brown pearl[i.imgur.com], another variant[i.imgur.com]
Youga - Util Light Brown pearl[i.imgur.com], another variant[i.imgur.com]
Speedo - Util Off White[i.imgur.com] - NEW

Faggio - Util Dark Green pearl[i.imgur.com]
Faggio - Util SeaFoam Blue[i.imgur.com]
Nemesis - Worn Silver Grey secondary[i.imgur.com]
PCJ600 - Police Blue secondary[i.imgur.com]
Vader - Worn Taxi Yellow pearl[i.imgur.com]


Those that already come customized, yet not everything is obtainable.
Ruiner - Slate Blue secondary[i.imgur.com]
Sentinel - Slate Blue primary and secondary[i.imgur.com]
Sentinel - Taxi Yellow pearl[i.imgur.com]
Dominator - Util Silver pearl, Crystal windows[i.imgur.com]
Surfer - MP100 primary, Util Bright Red secondary[i.ytimg.com]
Surfer - Util Bright Red pearl[i.imgur.com]

When you apply a crew color on already-purchased metallic with a pearl, pearl stays there. You can use this to give extra uniqueness to your car. Below you see the list of colors that come with non-purchasable pearlscents.

Lava Red - Matte Yellow
Garnet Red - Worn Blue Silver
Sunset Red - Worn Golden Red
Cabernet Red - Worn Golden Red
Sunrise Orange - Worn Shadow Silver
Olive Green - Worn Green
Bright Green - Worn Green
Gasoline Green - Worn Sea Wash
Saxon Blue - Worn Baby Blue
Mariner Blue - Worn Baby Blue
Harbor Blue - Worn Sea Wash

Brushed Steel - Util Silver
Pure Gold - MP100
Brushed Gold - MP100

Some of wheel colors are named differently from the actual paint. Why? Nobody knows.
Anyway: a list of Rim Paint Name - Real Paint name - Hex
Hex can be used to create a car with matching rims.

Carbon Black - Graphite - #0F0F0F
Frost White - Util Off White - #999999
Garnet Red - Util Garnet Red - #4A1000
Dark Copper - Bronze - #4A341B
Dark Ivory - Creek Brown - #262117
Dark Brown - Worn Dark Brown - #171413
Bronze - Util Medium Brown - #3D311D
Dark Earth - Matte Dark Earth - #3B352D
Desert Tan - Matte Desert Tan - #706656
Yellow Bird - Dew Yellow - #A2A827
Lime Green - Matte Lime Green (yes, it's different from classic) - #418503
Pea Green - Securicor Green/Pea Green - #47783C
Dark Green - Util Dark Green - #0F1F15
Olive Green - Matte Forest Green - #121710
Midnight Blue - Matte Dark Blue - #030E2E
Royal Blue - Blue - #001B57
Baby Blue - Worn Baby Blue - #3B6796
Bright Blue - Ultra Blue - #0055C4
Fluorescent Blue - Fluorescent Blue - #00AEEF
Slate Blue - Util Bright Blue/Slate Blue - #1F1FA1
Schafter Purple - Bright Purple - #320642

In case you need a color matched with default underglow. None of neons share hexes with game colors, even from those non-purchasable.
List of: NeonName - hex

White - #DEDEFF
Blue - #0215FF
Electric Blue - #0353FF
Mint Green - #00FF8C
Lime Green - #5EFF01
Yellow - #FFFF00
Golden - #FF9605
Orange - #FF3E00
Red - #FF0101
Pony Pink - #FF3264
Hot Pink - #FF05BE
Purple - #2301FF
Blacklight - #0F03FF

This is something I think I discovered cause I've never seen any pictures or info about it online.
What they do, is "automatically" turn on at night.

But it's no wizardry, you just need to put a dark custom color (<10% brightness) on them.
Keep in mind that unlike with primary and 2ndary, you can put a different hex here without having to match body hex or using standard paint on the car.

It's nothing special, but I don't think anyone knows about this trick. Also helps to keep clean look of your car at daytime.

Here's an example with #050b0c. Same car with neons on at day and nighttime.

Screenshots of cars with custom colors, most of which are my own. For inspiration and showing off.
There're a few imgur albums with of factory color charts for certain cars done by me below as well.












 



Factory colors for Issi classic from Austin Cooper[imgur.com], Dominator GTX from last gen Ford Mustang[imgur.com] and Jester Classic from Toyota Supra mk4[imgur.com]

This should be just about everything you need for custom colors on cars. If you got any questions, feel free to post them in comments and I'll reply whenever I can.

Remember to always drive in style.