One great thing about Sketch is the ability to bring in black icons and quickly recolor fill to suit the UI I'm working on.
When I try the same in XD, filling the .png format icon fills the entire image space, including transparent area.
Am I missing something in XD that enables me to achieve the same thing?
Unfortunately we don't have support for this behavior yet. There is an open request for this feature which you can vote for here:
We would be grateful if you took the time to vote and add further comments there if you feel the need. This way, we will be able to better assess the need for the feature.