I'll ditto what Kevin said - Halimeda is very nice looking for a Macro. Gracilaria is a nice deep-red/purple color.
A couple thoughts--
- Calcareous algaes such as Halimeda, Neomeris, and couple others are dependent on calcium for growth, and as such, if not kept relatively small, will deplete a lot of calcium from a system.
- As far as a "macro tank" - be careful with your choices. With refugiums, I have found that there are always some algaes that will "out-compete" others. These are usually caulerpas. In essence, these macros can absorb more nutrients, and grow more quickly than the other macros - leaving little food (and space) for their neighbors.