Finding last occurence of Interior.ColorIndex 36

I have been searching for a formula to help me find the last time (most
recent) color 36 appears in a column of colored cells. Most of the time there
is no typed information and when there is, it is not the same for every color
36 cell. The cells are not conditionally formatted. C. Pearson's site is
great, but I can't find what I need. I don't want to change color, I don't
want to know how many times it shows up, I just want to find the last time it
is in the column. I could count down to find it, but there are over 15,000
columns spread over several worksheets. I have Excel 2003. I'm pretty
formula illiterate, it takes me days to get a formula to work and even then
I'm not sure how I got it to work.

In my reading it seems VBA (?) would work, I think it is what macros use and
I have cut and pasted from my macros to make things work, but I'm getting
nowhere fast with this problem.



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Many Thanks.