### Godot version

4.1.1

### System information

windows 11, mobile renderer

### Issue description

On Mobile Vulkan renderer, the clear color is 50% lighter than expected

See steps to reproduce and Minimal reproduction project below.

The box and background have the same color on Forward+ and compatibility, but not on Mobile
happens also in runtime on exported project, not only in editor preview

Images of the same scene from
compatibility:
![compatibility](https://github.com/godotengine/godot/assets/11915378/a874fa86-c16f-43ef-aed7-c2066b770ac1)
Forward+:
![forward](https://github.com/godotengine/godot/assets/11915378/e416f9a6-dfd4-4c47-bbc2-b552ca58f83c)
Mobile:
![mobile](https://github.com/godotengine/godot/assets/11915378/e28e2db8-f7c3-47e2-8c0a-44ce937c9270)


### Steps to reproduce

 - add a CSGBox3D with "unshaded" shading, and albedo of #545454
 - add environment with Background = Custom color and color of #545454

Box and background are not the same color

### Minimal reproduction project

[bg_color.zip](https://github.com/godotengine/godot/files/12174822/bg_color.zip)

if (render_buffers) {
		
		free_data();
	}
	render_buffers = p_render_buffers;
	ERR_FAIL_NULL(render_buffers); 
}
RID RenderForwardMobile::RenderBufferDataForwardMobile::get_color_fbs(FramebufferConfigType p_config_type) {
	ERR_FAIL_NULL_V(render_buffers, RID());
	RendererRD::TextureStorage *texture_storage = RendererRD::TextureStorage::get_singleton();
	ERR_FAIL_NULL_V(texture_storage, RID());
	
	
	
	
	RS::ViewportMSAA msaa_3d = render_buffers->get_msaa_3d();
	bool use_msaa = msaa_3d != RS::VIEWPORT_MSAA_DISABLED;
	uint32_t view_count = render_buffers->get_view_count();
	RID vrs_texture;
	if (render_buffers->has_texture(RB_SCOPE_VRS, RB_TEXTURE)) {
		vrs_texture = render_buffers->get_texture(RB_SCOPE_VRS, RB_TEXTURE);
	}
	Vector<RID> textures;
	int color_buffer_id = 0;
	textures.push_back(use_msaa ? render_buffers->get_color_msaa() : render_buffers->get_internal_texture()); 
	textures.push_back(use_msaa ? render_buffers->get_depth_msaa() : render_buffers->get_depth_texture()); 
	if (vrs_texture.is_valid()) {