How can I fix this problem. I think it has mites. There is red on the bottom of the leaves.
Yellow Leaves on Scheffelia Plant
Certified GKH Gardening Expert
This does look like mite damage. The simplest way to control spider mites is simply washing them off plant leaves with a hose, and/or spraying the leaves down with a few drops of dish soap in a spray bottle of water. These articles have other treatment options: