The Flat UI Colors website has 14 color palettes for a total of 280 colors, which works great on iOS. With Android, try the Material Palette, which is also the choice for developers to use.
This amazing ColorZilla on Chrome utility helps to find HEX code for any color on the website.
With the tools available, the same color theory and their impact on the human mood, you can create a palette that matches your application / website project.
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