Option for background layer in Liquify

I could find that option in Liquify but if there is none, it should exist:
When wanting to deform a shape in liquify, there is an option that we can turn on some other layer to be above or underneath the one we are currently working on. But there would be nice if there is an option of turning on some solid color layer beneath all of those so that we can better see how we are deforming current layer. Like shown in the image below, in this kind of situations it is difficult to see where the edges of inner part of the shirt, which is one layer, meets the front part of the shirt and to adjust the joint precisely. So if we had an option to turn on some solid color background (color that we can choose from a palette) that will be beneath all layers it would be very helpful