I would suggest a combination of fall with inconsistent temperatures and some overwatering based on the surface of the soil and the strong variation of red/green plus full yellow leaves. There also appears to be some branch loss lower down on the tree.
The colour variation is not the normal pattern for my Zelkova in the nursery. It may be prudent to monitor the watering and drainage carefully this winter. I would also consider a repot this spring if drainage is compromised.