If you want to know more about how to mix colors in GIMP, the following few pages will give you an introduction to GIMP's different color mixing palettes.
By default, when you click the Foreground or Background color in the GIMP Tools palette, the Color Picker displays a color palette to the left that allows you to pick a base color from a vertical slider and then select a variation of that color with different strengths of hue and lighter and darker versions.
The rest of the Color Picker dialog gives you tools to mix colors either by RGB or HSV values. The hexadecimal value of selected colors are displayed in an input field and this field can also be used to select a color if you know this value. Below the hexadecimal input, which is labelled HTML notation, are swatches of the most recently used colors allowing you to quickly select a previously used color without having to mix it again.
For most users this is perfectly sufficient for selecting and mixing colors in GIMP, however there are several other options available. While you may find you prefer the default methods for mixing colors in GIMP, you may want to try these alternatives just to see whether they can add anything to your workflow.
You may not have noticed the tabs that allow you to change to a different color mixer. When you open the color picker, towards the top left of the palette are five tabs with icons to distinguish them. On the next few pages, we'll take a look at the other tabs and the options that they offer for mixing colors in GIMP. Whichever of these tabs you choose to use, the main part of the Color Picker dialog remains the same, offering you familiar ways to override any selections you make using the displayed color tool.

