Yes, there's green coralline. Unfortunately, there's not a real good way to promote the growth of one color over another. Usually, the green pops up in areas with higher light, red in the lower light areas, and purple / pink fill in the gaps. There are some other colors, too, but red, pink, purple, and green are generally the most common.
Green coralline isn't bad, but if you scrape it off, you'll temporarily get it off those spots that it's growing. However, by scraping it, you'd likely only help spread it around even more. I guess you could shade it if you don't like it, but that's going to be about the only way to try to control it.
