Pigeon can eat any chicken scratch, or chicken feed,,, since you are in a bind for getting regular pigeon feed. Wild bird mix is an acceptable feed.
The red permanent band may be a designated year it was used in. That year should also be printed on band. Some pigeon associations used red color in 2018.
If you do find owner of bird,,,, ask if they really want the bird returned. Not all are willing to have their lost bird back,,,

and some don't want,,, or if returned,, bird does not get treated well.

It is up to you what you decide to do with pigeon>>>.
Many like QWERTY were happy to have pigeon returned.
WISHING YOU BEST,,,,,,,,,,,,,,,,,