Remodeling Dilemma

We purchased a 3200 sqf ranch home that has a 26 year old metal roof. The roof is still in a very good shape. We are adding an extension, and raising the walls of the middle section, so when all said and done 50% of the roof will have to be redone.

If we choose to go with the original color, then we’re still going to have a color mismatch due to fading of the older panels. Can we paint the old to match the new?

We honestly prefer a dark bronze colour than the current lighter slate colour. Can we have the new panels in dark bronze and paint the existing ones to match it?

Going with the paint option can save some money, but even if we get right now, in 10 or 15 years we will still end up with a colour mismatch as Air-dried paint will fade faster than factory paint that was dried in 750 degree ovens.

Interested in your opinion on what is the best option in this type of situation.

Thank you!