Compare Column B With All Rows In Column A If Match Place In Column C?

I want to compare two columns. I would like to see if the contents of column B appear anywhere in column A, for any amount of rows, and if it does, to place the match in col C.

So in the example below, red in B1 would be checked in A1 through A1000 or however long A is. When any row has red, place that match in that row for C.

This would be repeated until all rows in B are complete.

Example
Col A: red
Col B: red
Col C: red

Col A: red
Col B: blue
Col C: not found