Most of the engineering grade ‘white’ reflective vinyls are kinda silver before light shines back.
(then it’s showing back whatever colour bounces off it / bright white).
To dull it down to a grey you could put a pale grey transparency (print) over it
I would say a silver vinyl next to a reflective white are pretty much indistinguishable in daylight, if you want a greyer appearance then overlay a transparent printed grey as David recommended.
Please note:
This action will also remove this member from your connections and send a report to the site admin.
Please allow a few minutes for this process to complete.