Disabled image button doesn't fade out in light mode

[ugosantana]

Hi there!

I'm using image buttons for a toolbar. In certain conditions, some of them are disabled. When disabled, the images should fade a bit. They do, but only in dark mode. I'm using egui 0.31.1.

I compiled the program for Mac and Windows, and in both cases this happens only in light mode.

I believe it is a bug... I attached an image to show what I'm talking about... (Is there a workaround this? Control the transparency?)

[lucasmerlin]

Interesting, I can also reproduce it on egui.rs:

Screen.Recording.2025-03-27.at.13.19.42.mov

[lucasmerlin]

I guess to fix it we'd need to change Ui here to set opacity instead of fade_to_color:

egui/crates/egui/src/ui.rs

Lines 523 to 526 in f4dcb99

	if self.is_visible() {
	self.painter
	.set_fade_to_color(Some(self.visuals().fade_out_to_color()));
	}

This would also fix a TODO:

egui/crates/egui/src/style.rs

Lines 1055 to 1060 in 5d6aaa2

	/// When fading out things, we fade the colors towards this.
	// TODO(emilk): replace with an alpha
	#[inline(always)]
	pub fn fade_out_to_color(&self) -> Color32 {
	self.widgets.noninteractive.weak_bg_fill
	}

I guess the problem with the current implementation is that weak_bg_fill in light mode is a bright white, and tinting a image with bright white doesn't do much

[ugosantana]

It would be great if it was an opacity change for the image, not a tinting!

[emilk]

• Closed by Change ui.disable() to modify opacity #7282