I have a set of data:

A B
Car1 12
Car2 19
Car1 11
Car3 31
Car1 9
Car2 22

I need column B to flash up RED if Car1 is 10 or less, Car2 is 20 or
less and if Car3 is 30 or less. I have no idea where to even start on
the formulas.

If anyone can help it would be great.