At age 1 we threw out the bottles and went straight to sippy cups with milk - it was never a problem for our kid, however we had been introducing the sippy cups for a few weeks along with the bottle.
As far as 'needing' to get all the colors in the rainbow? I don't think that's absolutely necessary but it is a good idea. In doing so, depending on what you feed, your daughter does receive a wide variety of vitamins and minerals (please do not include junk food in colors...typically this refers to vegetables and fruits) not to mention you introduce her to a wide variety of food items and hopefully have someone who has an accepting, expanding palate. You don't have to do the rainbow thing on a daily basis; over the course of a week is just fine.
Right now, and this is just my opinion, make meals fun and pleasurable. Enjoy healthy eating together as opposed to pushing and forcing, begging and pleading, because the last thing you want to do is make mealtimes and eating stressful. Offer her loads of variety but don't worry if she turns her nose up at things. Keep offering and follow her lead. And, it also helps if you eat the food too - kids like to imitate and please that young, so be a good model!