You're going to need 1-2 more shields and at least 2 more glasses. You absolutely have to have card drawing to make a rainbow deck work. One hourglass is fine if you get it early and protect it, but that will almost never happen. Quintessence is also your friend, saving you from the heartache of lobotomize, gravity pull, congeal, etc. I'd look at PuppyChow's or Ivalmian's rainbows as a template to build from. Your healing potential should be fine, though.