Color palettes and how to design one for a game

Ive delved inside 2d art and decided to make a project based solely on my art. Ive read about designing objects in a game using a color palette. Ive tried some color generators but dont understand the concept in them.
(e.g color.adobe.com ). Lets say if youve decided a shade of a color for a project, and you want to paint something blue, how would you pick the shades of this blue?

 

Look up color theory. Might help. Might confuse. Basically you can use those online palette generators to define either your full (and very low color) palette or use those as base colors.

If you want more colors you can either slightly adjust a base color by playing with hue, saturation or brightness to generate a variation on the base color. You can also mix your base colors by grabbing one drawing a little square then selecting another base color and drawing over that square at 50% transparency. Really it is up to you how you use them. I am sure the real artists can give you better help. This is just a general idea of how I do it... when I bother to do it.

 

I'm actually interested in the technical feasibility and potential approach of assigning color swatches to either sprites or potentially even 3D models based on greyscale values. In other words, you paint a texture using different greyscale values, and have a series of variables to define greyscale ranges. You then assign a different color to each of the ranges, and have the texture render with those ranges having the color adjusted for those pixels.

This would allow you to have different color palettes assigned to different characters, and allow for re-coloring characters as needed. (in a more dynamic fashion) I'm certain this has been done before, it's just been a while since I've looked into it. I imagine some manner of custom shader would be the normal approach.

 

I approach graphics work in a sort of similar way using only shades of gray that I then recolor. Not sure why exactly just find it helpful. Well particularly for 2D and wanting to light objects manually. Then it is easy to make a few copies and try out different color combo. Again though non-pro here and oddly not that often for games; mainly just when I am messing around doodling for the heck of it.

 

It's a fairly common technique, and has been used for a long time (used to do it a lot back in flash). The implementation is relatively trivial, the complex part is the design of the system. Well, not complex exactly, but requires a decent amount of planning. We used this approach on Commander, since we didn't use any lighting, and wanted time of day, and planetary specific coloring to have a nice blend on different planets. :

We basically stored gradients instead of single colors, that way we could have transitions through out the day. The models had an texture that controlled what part of the texture was affected, and by how much,

 

That's easy, just sample a palette texture (set to point sample) with the graycale color, that is the gray value is the U value of the UV of the texture that would be a 1x256 sized texture. You can stack multiple palette on the V and then use another method to sample which palette to use for a given model (vertex color channel?)

It's a trap!
Don't do that red green contrast are delicate thing to handle, they tend to vibrate and give headaches.

The truth is that you must not think in term of color in the beginning, but in term of contrast, readability, separation of plan and shape, cohesion of objects. In general we compose around three level of colors, the "background", the main color and the accents, as much for the general composition and the objects composition. And thinking of color mean to think in term of parameters of color, generally hue, value and saturation, and the contrast between them. Actual color are used for the symbolic and psychological effects, aka the mood and atmosphere.