What motorway signs are you talking about exactly? Motorway sings are blue, signs on the Urbaine are white. Example:

https://www.mapillary.com/app/?lat=33.55733574775081&lng=-7.606979207207019&z=18.576405608437643&pKey=470225117402431&focus=photo&x=0.4972244621735865&y=0.5716274065291669&zoom=0