While I agree the Empire should use minimal color, it just doesn’t make sense to wear white. Besides, it’s already been implemented in some weird way with the shoretroopers.
The white was intentional, and there is no logical need for changing either.
And just because Disney got away from many of Lucas’ concepts, does not mean you have to change Lucas movies to resemble Disney’s ideas.
Not to mention this Shoretrooper idea by Disney is idiotic. There is no hiding on a beach. But they can sell more Stormtroopers for sure.