Quinacridone magenta and winsor violet (dioxazine violet) are two of my favourite colours that I use in flower painting which are great for irises and pansies. I've used them most recently in a painting of anemones which is now available as an individual lesson and in the course extending your watercolour techniques.
There is an interesting article on the origins of Quinacridone magenta on the Winsor and Newton website which I've included in this blog.
Looking at the origins of these beautiful colours Winsor and Newton have written a series of 'spotlight on colour' articles, this is the link to the spotlight on quinacridone magenta.