Love the idea of changing up the chart coloring. I spend a lot of time in RL working in marine navigation, and if you need any input, I would be glad to help.
An example of "modern" chart coloring is here:
http://www.charts.noaa.gov/OnLineViewer/18721.shtml
Most charts stick to the pastel shades because they are still discernable under red or blue lighting, which was commonly used to preserve night vision. Many different shades of blue to signify depth would wash out under blue lighting, which is why deeper water is white on modern charts.
Not sure if anyone is interested or if I'm just babbling. Just in case you wanted to know.