Arcobaleno is Italian for rainbow, and means "lightning bow," but the latter part also sounds like "balance." This location is roughly the inflection point, or balance in some ways, of two arcs in the curving of Evelyn Avenue through this stretch.
Two arcs call for two rainbow references, so this location also first caught my eye by the brightly colored map of this Sandalwood complex (I was first pondering a Rainbow Sandals tie in, but it remains only this mention), and the second reference is the colorful construction fencing ads, at the time of this cache placement, for the Prism complex being built just up the street (that led to the demise of Evelyn's Cache; hopefully a replacement can emerge later!)
Congrats to gw0143 for FTF right at the 40mins mark after published again! He's got a bead on my arcos...