Hi kkb337,
I'd use the chair rail as divider of two shades of the same family
Two suggestions (the references are Sherwin Williams colors)
SW 6064 RETICENCE (above)
SW 6066 SAND TRAP (below)
SW 6078 REALIST BEIGE (above)
SW 6094 SENSATIONAL SAND (below)
I illustrated this last combination in this image
Hope this helps