This is certainly not impossible. I am assuming that what we are talking
about is colourcoding the cell when the choice has been made.

You would need to use the onchange event of the sheet, test it to see if it is
that cell that has changed, then, if it has you would colour the cell however
you wanted to.

One way of doing this woould be to use the validation  table and put the color
name in the cell to the right of each person, then you could do a
worksheetfunction.vlookup to get the colour name.

We may be able to help  you further but need a bit more info:

How many cells are there which use the validation method. Where are they.
How would your color  scheme be worked? i.e. all individual colors, groups, or
what.
How many distinct colors do you need.