In this project Markus shows us how he build a 7 segment RGB LED display by replacing the individual leds of the display.
7-segment LEDs are available in red, green, yellow and blue (maybe even in white?). There don’t seem to be any in RGB though, so if you want to dynamically use different colors in your project you either have to use multiple devices or use a different technology.
So this seemed like an opportunity for a nice DIY project: Why not take an existing 7-segment display, remove the original LEDs and add some RGB ones?
7-Segment RGB-LED – [Link]