I2C or serial - 2 or more Colorduinos

Projects General Guidance
1

Hi,

I am thinking of building a colourful digital clock by using a DS3231 clock and using an uno/mega to drive 2 or 4 Colorduinos. I do have questions which are not entirely clear from my searches...
It all looks possible and is referenced to but no clear projects or code, that I have found

The uno will communicate with DS3231 via I2C (already working)

  1. Should I use I2C or serial to communicate to Colorduinos ? My question is really about speed - is I2C fast enough?

  2. Can someone point me to any code/sketches where an uno is controlling 2 or more Colorduinos.
    The questions I have are addressing and whether the colorduinos need coding themselves if driven by an uno (or mega).

Thanks in advance

2

WTF is a Colorduinos?
Link please when talking about obscure boards.

3

I believe Colorduino has been around for a while.
Or maybe I'm thinking of Rainbowduino
http://www.seeedstudio.com/depot/Rainbowduino-LED-driver-platform-Atmega-328-p-371.html

So much stuff out there. A specific link always helps as you say GM.