When knitting with two colors, there are several options for holding your yarn to get the best tension and speed. This video does a good job of showing you how to hold one color in each hand, giving you the ability to knit without dropping one yarn to pick-up another. This approach is a combination of knitting continental with one color and throwing, or flicking, with the other color.
Fair Isle knitting and knitting with color really opens-up the possibilities for you. If you've been scared to try knitting with two colors, then try practicing with some swatches and you'll see how fun this type of project can be.
Want to improve the speed and tension of your fair isle knitting? Here are a couple of tricks that I find useful.