It is difficult to say the result of guppy hybridization. In principle, the combination of red and blue you mentioned has two results, red with blue spots and blue with red spots. As for whether it looks good or not, it's hard to say. Because guppies are one of the most hybrid fish, many so-called purebreds are also high-quality varieties that have been solidified after long-term crossbreeding. Red and blue combined with Brazilian red and big-ear mosaics are very beautiful.