Is there an easy way to copy and paste a color? I keep having to remember the RGB values and it's kind of a pain...
For example, if I make a circle shape and set it's color to 123 44 5, can I somehow copy that value and paste it onto a triangle shape I make in a different file?
Pixelmator uses the native Mac color picker. As a result, you can actually save colors using the picker itself.
For even more convenience, you can also use the eye dropper from the color picker to pick colors from anywhere on your screen.
I've recorded a quick GIF screencast for you.