Most of us apply color to a line or outline and/or to the interior of closed shapes. A color palette is like a font menu. When your color palette refuses to play nice with your project, all you have to do is mix your own colors. It is possible then to save your colors to an existing palette or even create custom palettes for your jobs. I usually save all the trials that led me to the final solutions and sometimes return to a color used in an earlier version. When a job is complete, it’s not a bad idea to make notes of the CYMK values of each of the final colors.