Not that bad aesthetics aren't a problem, but I think loss of basic functionality is a bigger issue.

Meh, Fisher-Price was cute. I've never understood the fascination for those drab Windows 3.11 grays.

And Fischer-Price was also functional, you just got extra colors.

I never understood the fascination with everything being forced white. The gray widgets and white content were perfect for drawing the eye to the important parts, ... the content.

In addition, the "classic" desktop of XP time wasn't flat grey. It was a warmer color, with a bit of beige. Wikipedia says image says #d4d0c8. Which was a lot nicer on the eyes all day long. How far backward we've come. Forced into narrow choices by folks who never heard of "Chesterton's fence."

Windows 3.x by default had colourful (yellow) borders and white backgrounds (except maybe the "main container" window in MDI apps; was that perhaps gray? Or teal?). The grey came with W95. Both were fully user-configurable via a quite user-friendly dialogue box, as were NT 3.x, NT4, and W2K.

Can't recall whether XP, Vista, and 7 also allowed you to change colours directly -- if it was only the "Fisher-Price", "Glass", and, uh, "Glass 2?" that were locked-in in the standard UI setting -- or if you needed to switch to "Windows Classic", the 95--W2K-style UI, to change even the colours. Can't recall, because I of course switched to Classic first thing I did on any of those.

That all went away with Windows 8, of course, and AFAIK didn't come back on 10 either. Actually, they'd started to sabotage it a little earlier: About halfway into the lifecycle of W7, you couldn't change the window border width in the dialogue any more; you needed to hack that value in the Registry (and re-hack it after any change via the dialogue box). And towards the very end, even that hack didn't do anything any more.

XP for sure allowed you to change colors. The dialog wasn't even hidden, I think.

7 probably did, too, but the dialog was a bit hidden.

Yeah, it was probably either the dialogue before that, or (even more likely) a drop-down at the top of the dialogue that let you select "Classic".

It's utterly incomprehensible to me why the went and just ripped all of that functionality out in later versions.

(Also, why Linux desktop environments keep crowing about how many "themes" they have. However many thousands of them people cobble together... Just utterly pales in comparison to letting users set each detail of their systems up exactly as they want; that's in effect infinite "themes"!)

Not hidden at all. Right click anywhere on the desktop and hit "Personalize".

What we're talking about is probably not a secondary but at least tertiary or... Eh, fourth-level dialogue, buried at least three clicks deeper after that right-click. (Except in versions after Windows 7 it's nowhere to be found at all any more.)

Windows 3.x was white, it is Windows 95 that was gray.

Amusingly Win10 was the first time since 3.1 where using the color returned for GetSysColor(COLOR_WINDOW) would give you a "correct" color for the window background :-P.