Interfacer - Collection of more than 200+ free design resources
Encycolorpedia - Providing hex color schemes, paint matching & search, color directory and color space conversions.
Facebook Design Resources - A collection of free resources made by designers at Facebook
Perbang - Perbang is an RGB and multi-tool chart that allows you to have extensive color schemes that can be shared and downloaded with ease.
Freebiesbug - Collection of the best free web design resources.
BeautyColorCode - BeautyColorCode is a reliable platform for getting your colors right, courtesy of the extensive color scheme library that is easy to share and download.