Material Maker - Cross-platform, procedural texture generation tool.
Color Hunt - Curated collection of beautiful colors, updated daily
Substance Designer - Substance Designer is a node-based non-destructive application for material authoring.
Material Palette - Generate and export your Material Design color palette
Filter Forge - On the surface, Filter Forge is just a Photoshop plugin, a pack of filters that generate textures...
Coolors.co - The super fast color schemes generator! Create, save and share perfect palettes in seconds!