One of the most difficult tasks for any photographer is learning how to expose flowers. There are certain colors that make it rough to expose to maintain detail in the highlights of the delicate petals while doing the same in darker areas of the composition. I find it better to underexpose the lighter petals knowing that I can post process for more detail in the shadows. Once detail is lost in the highlights it’s almost impossible to bring it back. Yellow, red & bright orange flowers in harsh sunny lighting are the worst. Try shooting flowers in the shade if you’re stuck with clear skies and too much sun. Remember to underexpose by at least 1/2 an F/stop. Examples below. The first two photos were taken with a Nikon D800 and third shot of the red tulip was photographed with a pocket Leica V-LUX 20. I lost a tiny bit of the highlights on the tulip photo but control with the tiny sensor in a pocket camera is more difficult than with a full sensor DSLR such as my D800 shooting in RAW format. Remember that a RAW file contains 256 times more information than a Jpeg.