I don't know about the Red Brittle Stars, but there is a brown or black brittle start that is reef safe.
Here's some information I found on Red Sea Stars:
Red Sea Star
(Formia milleporella)
Quick Stats
Care Level: Moderate
Tank Conditions: 72-78°F; sg 1.023-1.025; pH 8.1-8.4
Temperament: Peaceful
Max. Size In Aquarium: Up to 5"
Reef Compatible: Yes
Diet: Omnivore
Origin: Indonesia
Family: Ophidiasteridae
The Red Sea Star, or Red Starfish, of the genus Fromia may be various shades of red. It has multiple black pores (dots) on its surface. The tips of the arms are the same or a lighter color than the rest of the arm, differentiating it from Fromia indica.
It generally lives alone, but if the aquarium is large enough to support more than one, it will tolerate others of its own species. It requires a mature tank with algae and is generally fairly self-sufficient in the aquarium, finding enough micro-organisms and detritus to scavenge if live rock is present. It is diurnal. It is intolerant of copper-based medications and high levels of nitrate, and is very sensitive to changes in specific gravity, temperature, salinity and pH of the water, and oxygen levels. Avoid exposing a Red Sea Star to air or sudden salinity changes, as this is detrimental to its health, often resulting in bacterial infections and necrosis of an arm, or possible death.
The Red Sea Star is extremely difficult to breed in an aquarium, with no distinguishing characteristics to help differentiate it from its mate.
If there is insufficient algae growth in the aquarium, the diet should be supplemented with flaked foods, and small pieces of fish or mussel.
Approximate Purchase Size: 3/4" to 1-1/2"