I'm confused. The CF solution I gave you does exactly what you're asking
for.

In article .com,
wrote:

My problem is that I want to make every cell relate to the one to the
left of it and only that cell, so that the conditional formatting that
happens in C2 depends only on the data in B2. Then I need to copy the
same criteria down the whole of the C column, so that C3 only relates
to B3, C4 only to B4 etc. I have tried using a formula =LEN(C2) but
the results this gives bear no relation to my table.