Well, you could dye it, but that could get real expensive.
The brown color may be from tannic acid. Do you have a lot of trees in the watershed? Any pines? Of course, it could be turbidity from recent rain events, from undesireable fish species, or from suspended clay particles. There are solutions to all of these problems, many of which are not all that cheap for a 16 acre lake.
You could fertilize to make your lake green, assuming your alkalinity levels are o.k. If they are not, you would need a lime application. Check out my post under "Fertilization" for more information.
You may need an on-site professional opinion to answer your question.