Richard, I wasn't sure whether you were asking about composition or availability. Winsor & Newton has a Light Red. Depending on your monitor, you might find this color chart useful:
www.winsornewton.com/pdfs/cc01.pdf
Note that Light Red isn't in what we might regard as the "reds" on this chart.
By the way, this is NOT anything like a "red light" (as in "cadmium red light".)