This may be for eye protection, not team identification.
grey is not a colour, it is a neutral
The most popular colors of uniforms for Little League football teams is often white or black jersey and either black, white, or grey pants. Other jersey colors include red, grey, and blue.
it is silvery grey but mostly grey
Permanent colour doesn't wear off. Your natural colour grows out. If you were grey before you dyed your hair then the roots will grow out grey. Colour doesn't make your hair turn grey.
the final result influence the grey colour
The colour grey is a tone between white and black.