For Billy--the "grey" gene which is as consistent and solid as the "champagne" gene

Above is an Arabian foal with the grey gene. In the photo above he looks to be about a yearling. In the photo below of the same horse at what appears to be the age of 2 or a long two you will see the coat color change into what is often called a rose grey. My personal preference in a steel grey color(black into grey) which will often have dapples of varying grey color. A rose grey very seldom ever dapples instead having a "roaning" affect. This horse will never be completely greyed out like a Lipizzan, although he will get greyer as he matures he will always retain a slight bay/red tint to certain parts of his body often times in the hip and neck/shoulder area. Would you refer to him as a bay horse because of the color he was born with and exhibiting the bay characteristics of black mane/tail and points(lower legs)?
I also don't think we should refer to lions as "white" because they may have been "almost, close to, kinda, purtnear" white as a Polar bear cub when it was born.