Black with black rear number plate?

[YorkshireHill]

Spotted a black A2 which appeared to have a totally black rear number plate. Can this be so?

Only a brief view but couldn't see any numbers or letters on the registration plate

Southbound on M1 between Leeds and Wakefield. Overtook me just before Jct 39

Interested to know if anyone from here . . ?

 

[MikeMarsUK]

Black number plate with silver numbers = Guernsey if I recall correctly.