Start menu icons appear inconsistent and a gray background is added.
Windows 10 has a feature where they adapt an icon's background on the start menu to compensate for any contrast issues.
Something in the colour value of some of the Adobe Suite's icons sets this off.
The fix would be adjusting some value to make it not clash.
Sam Hardy commented
I've tested this theory and have created a new icon that doesn't set off Window's dark mode adjustments.