The best replacement for rainbows is reefs.

The best alternatives to rainbows are rated as following:
★★★★★  reefs
★★  ok computer
★  brownies
★  birkenstocks
★  king of limbs
★  bends
★  beavers
  havaianas

Your alternative for rainbows is not listed? Suggest!
Speaking about rainbows, one probably shouldn't forget about clouds.

Other search terms related to rainbows and their ratings are:
★★★★★ clouds
★★★ crystals
★★ rain
★ unicorns
waterfalls
You have in mind a companion for rainbows and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of rainbows in all years. Click on graph for more.
rainbows
reefs
ok computer