High-power LED strings on timer

Hello,

I have 2 strings of high-power leds (3 blue and 6 white , forward voltage 3.0 V) and a constant intensity driver (350mA) to power them. What I would also like to use a timer circuit (MK188) to alternate the blue and white strings (e.g. I would set an 12 hour-blue 12 hour-white cycle on the timer).

How can I make this work? I have a couple questions right now:

1. The MK188 takes a 12-24 V/ 10 mAmps to operate - how do I connect it to the constant power source?
2. the blue string will take about 9V, the white string 18V. When the timer will switch from white to blue, I think it could blow the leds, due to excessive voltage.

Thank you,
Alin