Bumblebees on Phacelia Tanacetifolia
Gathering the purple pollen on the hind leg pollen baskets
Some bees have yellow pollen from other flowers they've just come from
The purple pollen will be added on top of the yellow
The next photo shows some mites on the back of a bee's neck where they can't be easily removed by the bee.
Some mites are harmless and some may even act as cleaners
A bee with it's mouth parts extended as it approaches a flower.
It also has a mite on it's side
The next three images seem to show what I assume could be purple pollen or some other element of the flowers on the bee's extended mouth parts.
Specifically on the front of the galeae.
Various photos