So here is the latest:
If you want to change the seat belt color.....
-You can give IND a call/email and get a quote(not for the faint of heart). This also included a 'core'(your seat belts).
-You can also buy a new OEM set front and back($461) from Tischer(what I did, see attached) and then send to IND or a certified seat belt repair shop to exchange the webbing while keeping all the OEM parts. This way you don't have to have your car down for several weeks while you get the webbing replaced with what ever color you choose and you also have the option to swap back to the black ones.
I am still waiting for the OEM belts from BMW 2-3wk back order. I will update when I get them in. All the part #s are listed below. I didn't know you could order 'gray' belts for the M3. If they look good I might just do a straight OEM swap.
****PART# Correction for FRONT belts per my local dealership that is doing the install.
1 72-11-7-284-364 RGHT FRONT UPPER BELT WITH FO: 721011
1 72-11-7-284-363 LEFT FRONT UPPER BELT WITH FO: 721011