All grass blocks were originally like that, white and stuff, but tinted with a colormap of it's own.
That is a glitch in the coloring of the item form, probably an update or a bug to the colormap of the item form. #unfilteredgrass
It's their default mode, without a green biome exclusive tint, I think it cannot recognize a beach as a biome for the tinting! Ever thought of that? Just like villagers using plains biome soon for netherra and end, the grass uses none, OMG not a good analogy, but yeah, it cannot perceive the beach as abiome for the tinting, therefore it is deriving a gray color from the resource pack #unfilteredgrass
And, when in survival, you lose the snow, lol.
Yeah, strange😒