I've been using and experimenting with Glut for years. I've dosed glut at a rate of 1ml glut to every 3/4 gallon daily for extended periods in high light tanks (my 220g). You don't just start using that high amount and you have to be aware that some fish such as small cory species and inverts can be sensitive to high dosing. So no, you are not dosing too much. Your tank will actually tell you if you overdose glut as the water will almost immediately cloud up and be clear by the next day. I've never had fish loss and my fish still spawn even in high dosing. I've been doing planted tanks for over 30 years.
The higher the light in a tank, the more CO2 or liquid carbon, and ferts are needed to supply plants what they need during faster growth in higher light. Also the higher the lighter the shorter the photoperiod. With the current lighting you are using if you don't want to high dose Glut daily using DIY CO2 would help a lot.
Actually higher phosphate levels and lower nitrates will allow plants to color up under high light. Phosphate is what plants use to change green plants to yellow/orange/pink/red. The color is like a sunscreen that protects plants under high light. You can check out my albums to see how intense colors can become. Iron is important but IMO phosphates are more important. I keep nitrates at 10ppm and phosphates from 3-5ppm. I don't add extra micro's including iron, just the normal weekly dosing of the dry ferts.
I also do not suggest using actinic lighting as it is in the very high blue spectrum which plants can't use. Plants do best in lighting from around 5000K to 10K.