Window > Settings/Preferences >
Color Settings
The Color Settings window has three tabs. Each tab allows you to change the default colors for a different set of components.
Use the General tab to change the default colors for components in these areas: 3D Views, User Defined, Ghosts, IK/FK Blending, Heads Up Display, Animation, Animation Editors, Multilister, Render View, Hypergraph / Hypershade, and Outliner (Also affects Animation and Relationship Editors).
Use the Active tab to change the default colors for components in these areas: General, Objects, Components, Deformers, Manipulators, Animation, Artisan Brushes, and Smooth Mesh Preview.
Use the Inactive tab to set the colors for objects that are not selected. The Inactive tab lets you change the default colors in the following areas or tools: General, Modeling, Objects, Components, Deformers, and Animation, and Smooth Mesh Preview.