ken if you want to get the blue out of your fts, change the angle that your shooting at, in your pics you can see your light from under your black plastic trim, try getting down on one knee on an angle that the trim covers the light.
when your taking macros its easier to get the right angle as your so close, so when your lined up for your macro shot and the colours are there, slowly walk back untill the color turns to blue, this is where the angle needs to be changed, while standing in the spot where the color dissappeared play with your cameras "angle to tank" by going higher or lower and left to right, when you get the color back you can move back again.
of course now things are far away and hard to see so you will need to zoom in a bit
tank looks great buddy