Shift Work Calendar - Conditional Formatting Formula

Hi, I'm trying to create a shift work calendar. I've attached an example of what I'm trying to achieve but please note it doesn't work as required...

I'd like to use the information on the "details" worksheet to control the conditional formatting on the "January" worksheet.

eg. I want the conditional formatting formula to look at the name in cell B8,B9,B10 etc. then match and look up the information from the "Details" worksheet (start date, shift pattern, shift code).

If an employee changes eg from Shift1 to Shift2 the conditional formatting colour would also need to change (four shift patterns, four different colours)

Any help would be much appreciated.