Ken I agree, the colors are more muted at dusk. Here are the blooms this afternoon, taken on an overcast day. The colors are more vibrant, and I noticed the older blooms on the rainbow shade are darker. All the blooms have a wonderful scent.
Orange Shade
Pink Pudica
Rainbow Shade
Celadine- I noticed the outside of some of the blooms have a dark ping streak
Pink pudica- my 2nd plant is starting to bloom
Vishanu Gold's inflorescence, it's been blooming on and off all summer, but I haven't capture it open