mixture of red and blue stands out amongst colours as being the
most elusive of all. Many people have great difficulty distinguishing
violet, often selecting purple.
The difficulty in recognizing it in photography is compounded
by the problems of recording it.
is the darkest colours. When light it becomes lavender, and
when very dark it can be confused with dark blue and blue black.
If reddish it tend towards magenta - if less red it simply merges