Color Trends + Palettes :: COLOURlovers
Whats Its Color: Find the complementary and primary color of any image
Online RGB to CMYK conversion
Color conversion (RGB / CMYK / HSV / YUV / ...) | web.forret.com
Color Hunt - Color Palettes for Designers and Artists
Picular
Site Palette – Get the essential colours from a website
Adobe Color CC
HTML Color Picker
Color Picker by WebpageFX
Color Hex - ColorHexa.com
ColorPicker.com : Quick Online Color Picker Tool | HTML Color Codes
Colors & Fonts