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

Trianglify Generator

Best Flat Colors For UI Design

免费在线LOGO设计和配色网站

WebGradients is a free collection of 180 linear gradients that you can use as content backdrops in any part of your website.

Curated gradients for designers and developers