Hello there!
You can have a look at the rules to see if that is against the rules, and first of all Yes, you can transform the tag color if the person lended a 300m but that will be rare since people dont want to get risked of scamming, But still you can transform the 300m to your friend then it goes to you then you give it to the person who lended the 300m.
Please do not hesistate to ask for more questions and we will answer it ASAP.
Sincerely,
Bahoji10