I think I would trace a section so I could reproduce it in pencil if needed. I would then wash a little section and see if the blue comes out. If it does you can put the lines back in with a pencil. If it doesn't come out I would use purple, blue or black perle cotton to embroider it. It is still called " Redwork" no matter what colour you use as long as you stick to one colour of perle cotton.
If you really like the panel and still want to do it in red, you could trace the pattern onto muslin and then you would have 2 panels to embroider. A win win situation.