Color printing requires a good quality, smooth, ultra-white paper. If you use a regular paper, the result will be mottled and poor quality. The formation of the paper is also important, as it determines the uniformity of the paper surface. The more uniform the paper is, the better your printouts will look.
You can set the printer to print in higher quality printing modes, but this makes it use more toner, thus making your work more expensive. It’s more cost effective to use good quality paper. In fact, paper only accounts for some 8-15% of the final printed cost. It’s like putting a two-carat diamond on a brass ring, definitely not worth it! Using ultra white paper such as Navigator (which is 169 on the CIE scale), results in much higher color contrast, and therefore a much better appearance.