### 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)

Button(p_text) {
	set_toggle_mode(true);
}
void ColorPresetButton::_notification(int p_what) {
	switch (p_what) {
		case NOTIFICATION_DRAW: {
			const Rect2 r = Rect2(Point2(0, 0), get_size());
			Ref<StyleBox> sb_raw = theme_cache.foreground_style->duplicate();
			Ref<StyleBoxFlat> sb_flat = sb_raw;
			Ref<StyleBoxTexture> sb_texture = sb_raw;
			if (sb_flat.is_valid()) {
				sb_flat->set_border_width(SIDE_BOTTOM, 2);
				if (get_draw_mode() == DRAW_PRESSED || get_draw_mode() == DRAW_HOVER_PRESSED) {
					sb_flat->set_border_color(Color(1, 1, 1, 1));
				} else {
					sb_flat->set_border_color(Color(0, 0, 0, 1));
				}
				if (preset_color.a < 1) {