The key feature being the colour is selected by clicking on an image, the RGB value of the pixel you click on is processed and sent to the audrino which then outputs that same value.
Obviously the match isn't perfect especially at darker colours as I'm yet to see any LED do black very well, but the project should hopefully provide some insight to those of you starting with arduino and other microcontrollers.
Feel free to ask any questions in the comments and I'll answer them as best i can.
Also as i am new to instructable publishing let me know any improvements i could make on this or future instructables.
Video below shows the final result: (if it wont play right click and go to watch in youtube)
Step 1: What You Need
Arduino or similar
1 x RGB led (Dispersed, i used some super fine sand paper as the one i had was water clear)
4 x Connection Wires
1 x Breadboard
3 x Resistors if you plan to leave this on for extended periods.
use this tool to calculate resistors specific to your LED led.linear1.org/led.wiz
(This can be done in other software packages but this instructable is to get people started with arduino)
Step 2: Setting Up the Hardware
Note: My RGB Led is common cathode, if yours is common anode the second pin should be connected to a voltage supply not ground.