Different eye colors, different bodies, different faces, different hairstyles, not even the skin is always the same.
But they
all seem to ever be rendered as a light-skinned woman with a blank, somewhat terse expression, and domed poofy purple/blu-ish hair with sideburns. Man, the Major is like the Thing. You can't ever really tell
what she'll look like on a given day.
Sonic does not change from blue to red and Mickey wears the same thing for decades even in the same colors
Sonic's blue coloring, eye color, body proportions, shoe type and details, gloves, and his accessories or lack thereof have changed far more times over the years than Major has, and
Major is older than Sonic. Subsequently, no one was ever really confused about who that blue hedgehog was because he has a few iconic markers... like being a blue Hedgehog. Same goes for Mickey, whose eye shape, ear positioning, coloring, shoe type, hand shape, body proportions, and gloves have also changed over the years too. These are all far more numerous and noticeable changes than what you've noted with Major, which makes me think you're taking the piss here and acting like no one knows what she looks like.
