Color correction for colour introduced by bouncing flash off non-white roof?

What are my workflow options for color correction? Many of the venues I shoot in I bounce flash off a non-white ceiling which introduces undesirable colour.looked at a few tutorials and all used non cheap software.I shoot for social latin dance events, generally unpaid and more as a hobby. Thought I'd seen some less expensive software discussed in a reddit once. Can't find it now.From memory the professional workflow includes using a greyscale card. I'm rusty as heck on editing. via /r/photography https://ift.tt/2unlEaE