New Light Fixture - Am I frying my Monti or not giving it enough light?

I have had this Monti for over 2 years, over the years I have reduced it and its come back healthy. Under my old fixture it is a rich orange. My old fixture was an Outer Orbit 48" with T5 4x54W and MH 2x150W. Total 500W on a 75 gal

The old fixture is dead so I went with a Tek T5 48" 8x54W. Total 400W on a 75 gal. The bulbs are mainly blue with 1 midday.

My question is whats going on with my Monti? Its developing spots over the last four days. At first I thought it was dying as it looked like it was deteriorating. On second glance the "bad spots" are turning purple not bleach white. So I am not sure if its light acclimation issues or its not enough....

I was under the impression hard corals thrive under good T5 only lighting.

Thoughts...

Anyone out there?

Oh yeah sorry... the monti was normally bright orange but you can see the purple spots. While the color looks good there is not much texture on those spots hence the reason I thought it was dying rather than growing.

Yeah I really like the light. Just having a hard time from a non-scientific standpoint thinking that less wattage and no MH is as good! But it looks great, no sound and light is pure. Miss the shimmer but good price and good look. Thanks