Fix SnapGrid is almost invisible in light theme

[jsjtxietian]

Fixes #85574

cc @MewPurPur Any suggestions?

[MewPurPur]

This was my mistake, I mixed this up with work on a snap icon for my own app (which uses #def as its icon color). I don't think I even intended to change this.

Godot's icon color is e0e0e0, so please use that.

[jsjtxietian]

Godot's icon color is e0e0e0, so please use that.

Thanks! I first use that too, but then find the other snap icon (Snap.svg) is #fff so I used that, should I change that too ?

[MewPurPur]

I just checked the SVGs, it seems to me like those icons are likely also slightly broken in light theme. There's no reason not to use e0e0e0 for them. So yes, I think they should be changed.

[akien-mga]

There seems to be a lot of icons using fill="#fff" (and some use #fff for stroke too.
If this should be changed to the remappable #e0e0e0, this might best be done in a dedicated PR. But I assume some of them use #fff intentionally to keep it white even on light theme (e.g. eyes of Godot logo).

$ rg -l 'fill="#fff"' | wc -l
87

[MewPurPur]

Let me look into it.

[MewPurPur]

I don't find anything else that needs to be changed. I should mention that #fefefe is the "forced white" color, white #fff becomes a dark gray when it's in light theme. And #e0e0e0 is the icon color, it's a very light gray, and in light theme it's a dark gray (but less dark than the one #fff becomes.)

A lot of the occurrences of #fff are outside editor/icons, which is correct and shouldn't be changed. In editor/icons, I also didn't find any occurrences of it being used for icons. It's commonly used for GUI elements (I consider it not icons, also opacity is used to determine how much those stick out) and for contrast, mainly for icons like Transform2D, which is just "T2D" as an icon and it uses a transparent white to add extra contrast to the middle letter, so as to unstick them and make the icon more readable. Also for icons like the overbright indicator, trying to have as much contrast as possible between white and black. These shouldn't be changed either (Actually, they could use #fefefe and get removed from the list of exceptions, but honestly it doesn't matter and it'll need extra care to make sure the other colors don't get messed up from it). Then there are the Godot logos using it for their eyes, obviously shouldn't be changed.

In short, I didn't find any other icons that need their fill color tweaked from #fff to #e0e0e0.

[akien-mga]

Thanks!

[akien-mga]

Cherry-picked for 4.2.1.