After vacuuming up a bunch of purple urchins, would it be possible to alter their DNA to be more like that of red urchins? Then release those genetically modified urchins back into the ocean to pass their “red-shifted” traits into the greater purple urchin population.

I realize there are plenty of ethical issues surrounding an attempt at genetically modifying an entire species. Perhaps doing so would be irresponsible? It’s not my area of expertise.