The heart of the mood lamp is the colour changing light. Bright LEd systems driven by complex microprocessor systems are detailed elsewhere in instructables but this uses a commercial easily available colour changing LED from www.Rapidonline.co.uk if you are in the Uk or search fro colour changing LED or rainbow LED in Ebay or google for your country i am sure you can find them. Here they are £0.56 or so each.
The LED contains a red - Blue - Green LED and a minute microprocessor inside a standard 5mm LED package - IT IS SMALL. All you need is to apply 3 volts to the LED to make it work.