Obviously most map colour schemes tend to use green for countryside, brown for built-up areas and blue for water, simply because that's what the vast majority of paper maps use.
But after that, there is great variation in the other colours used.
On the TomTom models, the user has the option to change between several built-in colour schemes for the maps, and if none of those suit, then you can create and add your own, or load ones made by others.
One of the major personalisations people will want are the colours of the different road types.
None of the built-in colour schemes match the colours used in the UK very well so I've added a scheme called "GB_New" which gives me the blue motorways I expect to see.
On Ordinance Survey paper maps, I think "A-roads" are drawn in red, but that would conflict with the red used on the TomTom for your chosen route, so I have opted for Yellow for all major roads and white for minor ones.
Other colours are used for paths and tracks, ferries, airports etc.
Most people probably opt for one of the built-in schemes, and possibly they simply choose one which has an overall "tint" or "colour cast" to match the colour scheme of their car!
Hope that's some help, we could provide some example pictures of the colour schemes available if they would be useful.
Also, you might like to look at some free PC software for creating and editing the colours used.
It's called "Colour Scheme Editor" and it can be downloaded from
here.
There are also lots of downloadable colour schemes available on there to try.
