different colors of coraline grow in different light intensities...the dark reds seem to like shaded areas, the purples seem to like brighter lighting.. also it is very common for coraline to temporarily bleach after adding new lights, it should grow back although it may not be the same color when it returns...just keep your water params in check. hope this helps, good luck
oh yeah, i think the bright orange seems to like the shaded areas too