A reprise of an earlier post:
Passive Guy admits sometimes he’s not so good with what colors go with what other colors.
He has a shirt/tie/suit system worked out so everything goes together, but that’s because he seldom gets adventurous in this color realm
Designing a cover is a different thing. Blue shirt/red tie/dark blue suit gets old very quickly in the world of book covers.
Fortunately, PG has located some color crutches.
The first one is kuler, a site sponsored by Adobe. Basically, it’s a site full of color swatches that are easily loaded into Photoshop, Photoshop Elements or Adobe Creative Suite.
Here’s what it looks like (click for a larger image):

This particular screen shot is for a color swatch called Honey Pot. If you like it, you just click a download button, then import it into Photoshop and you’re ready to go. There are a gazillion swatches and PG doesn’t know if they all work together, but he bets all the Most Popular and Highest Rated ones do.
Here are a couple of book covers PG changed by switching color swatches from kuler.


A quick note on PG’s book covers – You don’t want to use this many colors for a real book cover. PG was just showing how all the colors in the swatches work together and allow you to change the look of a cover design.
Maybe you don’t like any of the swatches kuler provides. Another website allows you to make your own swatches only it makes it hard to do them badly.
This one is called Color Scheme Designer. With this site, you start off with a color and it builds palettes of complementary and contrasting colors with a click.
We’ll start off with an aqua color.

This color has an RGB code of 37AEA5. You obtain the code in Photoshop by clicking on a color you want, then opening up the Foreground color box. You’ll see the color code for the color selected down at the bottom of the box.
So, you take your RGB code and paste it into Color Scheme Designer and the first thing you see is a monochrome palette. (Click for larger image)

The aqua we started with is the biggest block on the right side and you have several other versions in different shades. Color Scheme Designer lets you mouse over any color and read its color code. (Your monitor may not make the two colors look that way, but they started off the same on PG’s monitor before the screen shot went into Photoshop and from there to WordPress.)
From this point, you can generate colors very rapidly. PG clicked on the Triad color option and this is what resulted:

You can see some dots on the color wheel to the left showing where the base colors originate, then the website creates variations on those on the right side.
Here’s another variation on his book cover that PG created with the palette shown above:

At least to PG’s color-going-together impaired eyes, this cover looks plenty gaudy, but the colors complement or contrast with each other.
PG apologizes for the lack of any color perception science stuff in this post, but he distinctly remembers looking at his girlfriend while that topic was being discussed in 8th grade. He always appreciated her color palette.