Ive decided to add some colored LED's in with the landscape lighting where I work. It wasn't as straight forward as I had hoped and I ran into a problem finding a simple RGB controller, and a simple way to power everything. My plan is to run everything (including the old halogens) off my existing 600w 12v AC timer, then replace a few of my 10w halogen lights with RGB's that fade between colors gradually.
Here's the final parts list now that its done.
(12) Cree MC-E RGBW's, From Joydeal on eBay
(4) 3W 3-LED 270-Lumen Waterproof Flood Light/Projection Warm White Lamp (12V)
28-Key RGB LED Dimmer Controller w/ Remote Control (DC12~24V)
150W DC-DC 6-32V - 0.8-28V Buck Boost voltage regulator (Crucial for boosting the low voltage AC to a usable level.
25A, 50V Full-Wave Bridge Rectifier
(4) 1000uF 35V diodes (from my bin)
LED Controller housing: I reused an old 600W 12AC outdoor lighting box.
Wire: (4) 50' lengths of 12G/4 braided wire from Home Depot.
All of the parts took less than 2 weeks to get here.