Luckily painting the middle section of the sunflower went without mishap this time. There are a couple more petals left to do but the sunflower part at least in nearly complete.
After looking at some more sunflowers in the florists I decided to paint the variety with a lighter middle section. To me the warmer yellows and orange/reds just seem to convey the warmth of the sun more than the variety with the darker middles. I might need to go a little darker in this section but I am going to wait to decide until I have completed all the petals.