Best Flat Colors For UI Design
RGB颜色值与十六进制颜色码转换工具，能将RGB颜色值与十六进制颜色码相互转换
提供渐变色和配色方案，还能从提供的图片中提取主要配色
Beautiful Color Palettes
Beautiful colored gradients
WebGradients is a free collection of 180 linear gradients that you can use as content backdrops in any part of your website.
Trianglify Generator
