The male White-tailed Bumblebee looks very different to the queens and workers. He has a white tail but also has lemony or straw yellow on his face, shoulders and upper abdomen.
He looks a lot more (pale) yellow, since he has yellow hair on his head, a band on the upper and usually also lower thorax as well as on his upper abdomen.
Sometimes the yellow band on the lower thorax is very thin or missing.
Many typically have this black double-barred effect on their middle abdomen.
Male White-tailed Bumblebees on flowers, including the yellow face
Male White-tailed Bumblebees on flowers
The characteristic double-barred effect