I find grey skies (without the rain, but just after), are ideal for flower photography. You don’t have that harsh direct sunlight, and with some camera control, you can get pretty close to the original and natural hues of your subject. Sometimes, taking a soft and gentle approach can bring about some beautiful details which contrasts with the mellowed, blurred background, especially when being this close to the subject.
This appears to be the very last flower of the season on a rose I planted in memory of my Mom seven years ago.
Photograph taken October 2016, rear garden, Staffordshire. © Pete Hillman 2016. Camera used Nikon D7200, with Sigma 105mm macro lens. Manual setting ISO 400. 1/250 sec. f/6.3. No flash, hand-held.