Implemented `HasColor` and `CanColor` for `RoundRectangleColorContext`
Implemented `HasColor` and `CanColor` for `RoundRectangleColorContext`

andrewcsmith/graphics,stjahns/graphics,aepsil0n/graphics,bvssvni/graphics,PistonDevelopers/graphics,Vinatorul/graphics,mitchmindtree/graphics,echochamber/graphics