You aren't getting any responses because this is a question that can't be answered directly. No one can tell you precisely how to set your lighting because there are too many factors, based on your specific setup. The good news is a wide variety of settings are probably OK.
Could you be more specific about what you mean by losing color? Is it bleached white, turning more brown, or are the bright pigments just less intense? Those all mean different things.
Note that lighting is not the only factor here. Changes in color can also be an indicator or deteriorating water conditions (are you monitoring the nitrates and phosphates?) or a lack of something in the water or food. There is also a chance the anemone was dyed, in which case the loss of color would be natural and possibly a good thing.
Assuming you are correct that the LTA is doing well, you should feel free to experiment with the lighting levels to see what works in your situation, or simply what looks best. However, if you choose to increase light levels, make sure you do it slowly, over a period of weeks, to avoid damaging the animal.
