I know that I can use conditional formatting to change the color of a cell,
but this can prove cumbersome for multiple cells and multiple values.

Is there a way to change the color of a cell based on a formula in that cell?

For example, assume I have cell A1 = 10 and plan on entering a list of data.
I want to compare each value to cell A1 and change the color accordingly.

I would assume the code would then be as follows:
=if(a2<a1,color=red,color=green)

However, there appears to be no command such as "color" or "fill".