Customize color key and ranges for slope angle shading

I'm significantly colorblind, an avid backcountry skier, and an ultra runner.  When I try to map out routes it can be very difficult to determine what the pitch is of the terrain with the current slope angle shading option.  For running, this can make it difficult to know how I need to train for certain courses.  For backcountry skiing, this can potentially put me in hazardous situations if I misread the map.  While I appreciate that 90% of the people using these maps wont have issues.  The 10% of us who do have issues are kind of stuck without a better option than checking the profile of a measured line, which can be very tedious and not the most accurate for long tours and races.

My proposed solution is to allow users to select the color of the ranges of slope angles so they can more significantly contrast with the colors of the ranges adjacent to it.  Allowing this to be user selected will allow people with different types of colorblindness to adjust the map to be more legible in their specific situation.  The default doesn't need to change, but a drop down of different color options could help a lot of people.  

Creating an adjustment of the ranges of slope angles shown could also be beneficial for situations like planning a tour on high risk avalanche terrain, where the user can set every angle above 35* to one standout color, so there is no question about what terrain is the most concerning and should be avoided.  Allowing the user to highlight certain pitches not usually shown in slope angle shading can assist guides who have clients who feel most comfortable skiing low angle terrain below 27*. (the current lowest angle shown in slope angle shading)  If users can select a custom range and a custom key, then guides and leaders of backcountry groups, colorblind people, and people searching for specific steepness in their terrain will all benefit.