Ive noticed the substrate color makes a big difference to the overall look of the tank. And also, may influence the way the camera captures the colors.
Good point on the substrate. A monochromatic substrate, whether it be light or dark, tends to make the plants "pop" more, and makes a scape seem more defined.
In your tank Linn, the Helferi is a good example. With a solid dark or light substrate they would "pop" much more.
As to Pro Mode settings, white balance and brightness make the most difference.
With brightness turned down a bit, you'll have less "washed out" areas where too much light causes hot/shiny spots, if that makes sense. Color will look better and deeper, and black background will disappear. Better to take the shot with less brightness, then brighten it up later if you need to.
With the LED's, you also might turn up the color channels. Big difference for me if my highly colored bulbs aren't on. Also, a dark room with no ambient light works best. IMO better to have full lighting for clarity, but adjust camera settings to compensate.
I've been using 4K white balance, but that's just trial and error to see what makes the pics look closest to what you are actually seeing.
But hey, whatever you did on that last one seems to be working pretty well already.