This page provide conventions to produce topographic maps.
Topographic maps, displaying an area's relief, de facto explain many other things such as human occupation, cultivated areas, kingdoms borders, exchanges ways, etc.
If you create a topographic map, note that these colorimetric values are indicatives. If need, you can adapt colours to your needs : if more altitude layers are needed, create new ones ; if less are needed, select just some allowing the best contrast.
Be also conscient that a topographic maps is first a background, which then will be complete by other layers. Most of time, these upper layers are transport ways (see exchanges maps), Kingdoms' areas or troops and moves (see areas maps & historical maps), or even officials borders from location maps.