### 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)

}
			}
			ginstance->instance_count = particles_storage->particles_get_amount(ginstance->data->base, ginstance->trail_steps);
		} break;
		default: {
		}
	}
	
	bool store_transform = true;
	ginstance->base_flags = 0;
	if (ginstance->data->base_type == RS::INSTANCE_MULTIMESH) {
		ginstance->base_flags |= INSTANCE_DATA_FLAG_MULTIMESH;
		if (mesh_storage->multimesh_get_transform_format(ginstance->data->base) == RS::MULTIMESH_TRANSFORM_2D) {
			ginstance->base_flags |= INSTANCE_DATA_FLAG_MULTIMESH_FORMAT_2D;
		}
		if (mesh_storage->multimesh_uses_colors(ginstance->data->base)) {
			ginstance->base_flags |= INSTANCE_DATA_FLAG_MULTIMESH_HAS_COLOR;
		}
		if (mesh_storage->multimesh_uses_custom_data(ginstance->data->base)) {
			ginstance->base_flags |= INSTANCE_DATA_FLAG_MULTIMESH_HAS_CUSTOM_DATA;
		}
		ginstance->transforms_uniform_set = mesh_storage->multimesh_get_3d_uniform_set(ginstance->data->base, scene_shader.default_shader_rd, TRANSFORMS_UNIFORM_SET);
	} else if (ginstance->data->base_type == RS::INSTANCE_PARTICLES) {
		ginstance->base_flags |= INSTANCE_DATA_FLAG_MULTIMESH;
		if (false) { 
			ginstance->base_flags |= INSTANCE_DATA_FLAG_MULTIMESH_FORMAT_2D;
		}
		ginstance->base_flags |= INSTANCE_DATA_FLAG_MULTIMESH_HAS_COLOR;
		ginstance->base_flags |= INSTANCE_DATA_FLAG_MULTIMESH_HAS_CUSTOM_DATA;