I have trouble with anything in those shades, but my skies are cloudless with low humidity.
Ted Blaney is a talented hybridizer and a rigorous selector, so I doubt he would have introduced a daylily with unacceptable sunfastness.
"Daylily Math" doesn't really work, but here are some things to consider.
I've grown both of the parent plants for over 20 years, and they hold up well in the sun, so there's a good chance that Raspberry Suede will do fine in that regard.
Vintage Bordeaux has heavy substance and good sunfastness. Red Grace has normal substance, but it's "tough", in that the segments hold firm throughout the day. The color is a beautiful, clear, sparkling red in the morning, but it does dull some when the sun hits it. Both have intense green throats.
I'd say that it's well worth a try. Where did you find it listed?
