WebGradients is a free collection of 180 linear gradients that you can use as content backdrops in any part of your website.
一个帮助大家选色、调色，提供色彩搭配参考，调色轮网站。
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
Best Flat Colors For UI Design
Beautiful Color Palettes
一款 100%免费的配色方案在线生成预览网站
Curated gradients for designers and developers
