A custom control with proper design-time editing facilities. Displays a colour gradient with user-controlled keys and colour choices, plus rendering and styles are controllable for both the colour bar and the keys. Programatically, the gradient can be sampled at any point to return an interpolated colour value. There is sufficent optimisation to keep re-painting efficient.

Shows usage of ParentControlDesigner, ISite, DesignTime Attributes and such to develop a custom control that integrates properly into Visual Studio.

Download the source and test application here. Built with .NET 1.1 and VS 2003, Tested against .NET 2.0 and VS 2005.