I have a cell that looks like this:
=IF(B23=B22,C22,"")

But what I really want is a Match function that finds the last match
between B23 and any row above it, and then copies the value in column
C to C23.

e.g.
B C
19 red 3
20 green 5
21 red 6
22 blue 17


How do I get C23 to enter a 6 when I enter "red" in B23?

Note: This spreadsheet will grow, I add a new row or two every week.