GDM-FW900 24" monitor display

I purchased this monitor used about a year ago for design & illustration purposes. It's been pretty good so far, but way more machine that I ever needed. Thus, my lack of enthusiasm for learning all it's technical ins and outs.

I am having a terrible problem right now with the screen color being WAY off. There is an overall blue-green tint to the display, and I don't know how it happened. I'm not doing all that well with using the adjustment button on the base of the monitor, so now I suppose I've messed even more up.

Can anyone help?