Make highway=track without tracktype a bit less visible.

[waterced]

• highway=track may be used for bike transit
• The actual usability of a track depends on the nature of the surface, smoothness, and so on. tag surface, smoothness and tracktype.
• These tags are currently rendered in a fashion that make it possible to see it a track will be praticable.
• However, an untagged track with only highway=track is rendered with dashes very close one to another, making look more 'ridedable' than tracktype=grade2 for instance, while this is only a question of lack of data.

A solution could be a dot-dash rendering for these tracks without more information, as it is done for traditional cartoOSM.

Finally, the color for tracks is very dark, which makes it more visible than highway=path&bicycle=designated.
Maybe changing the color (to a shade of brown? --edit--may no be a good idea, it is the color of pedestrian path--) could make tracks looks less attractive than actual bike paths?