Creating color palettes can be hard. Designers spend a lot of time trying to create cohesion between the various colors on the rainbow.
Color picker match colors related to your existing composition; leads to color scheme ideas; and generate color shades, tones and tints values.
One big piece to the puzzle is color theory. Beyond the understanding of color theory you also need to understand how to choose the right colors for your palette.
Understanding color is the first step to applying it successfully in your design. Color theory is a complex subject that analyzes how different hues/shades interact with one another. However a few basic tips can lead to finding that perfect palette.