### Godot version

v4.3.dev.custom_build [d76c1d0e5]

### System information

Linux

### Issue description

When opening the color picker by clicking on a color property the color changes slightly.

### Steps to reproduce

* Click on a property with value `Color(.5, .5, .5) ` in the inspector
* Click away
* Open the color picker again
* See the color change to Color(0.502, 0.502, 0.502) in the "RAW" tab

### Minimal reproduction project

[ColorChangeBug.zip](https://github.com/godotengine/godot/files/13545089/ColorChangeBug.zip)

for (int i = 0; i < modes.size(); i++) {
		delete modes[i];
	}
}
void ColorPickerButton::_about_to_popup() {
	set_pressed(true);
	if (picker) {
		picker->set_old_color(color);
	}
}
void ColorPickerButton::_color_changed(const Color &p_color) {