Obviously, projectors all use the same basic colors: red, green and blue. But the way they're blended and balanced can make all the difference. Imagine Luke Skywalker with yellowish skin, or a meadow with olive-drab grass! That's why colorimetry is an important criterion, since it is what gives a realistic quality to the images.
It's difficult to be objective on this point, however. The choice of a projector has to be guided above all by personal taste. Unlike other, less subjective factors, colorimetry is really a question of personal preference. Certain projectors have "cold" colors, while others lean towards warm colors, and still others can be red-dominant, for example. This overall tonality will be very difficult to correct through adjustment. On the other hand, it is possible to attenuate or reinforce the image rendering and correct certain minor faults.
In conclusion, you need to take the time to find the projector that appears most neutral to your eyes. Then you'll be able to take the time to fine-tune it to your taste.