Sometimes we are painting is such bright light, full sunshine on the canvas, looking at the finished painting indoors it will be darker than expected.
This is the case for this painting. My purple was so bright and all values 'just right'. I was painting on the narrow path so there wasn't really a way to turn the easel.
Will remember for next time to make sure to key everything lighter when painting in full sunlight. Yes you will say "try the umbrella".. but that too differs the colors and more stuff to drag along. I'll use the key in keying. ;)