I will suggest the developer to distinguish the backbone and side chains.
As I known, we don't have the function for it in the current version.
But I have an idea to hide H and distinguish the atomic type (hope it is possible to select the backbone or side chain) using the OPLS atomic tag.
The viewer usually cannot change the configuration. In the builder, you can edit the configuration.
In the selection Tools (Select by Element), you can select the H atoms and delete them with trash icon.
And using the Tags, you can select different atomic types.
In the Graphics Properties, you can distinguish the tags with wished color.
In the viewer, using color by coordinates in the color atoms, you can distinguish the chains with color map.
Unfortunately, it cannot distinguish the backbone and side chain.