Here is a good example of the breeding colors of a Little Blue Heron. I think these changes happen around April, they fade in mid summer. Even then their deep slate is beautiful (and so dark near impossible to photograph).
Even their bill takes on a vivid purple shade.
The ultimate image is to catch the bird up close, with bright sun behind them. I have not been that lucky this year.
This season a Little Blue colony has been nesting in a spot that is difficult to photograph. They prefer thickets. Still I have at least caught a few as they wander into the open.