Color relief — hypsometric elevation tint like a topographic map
Hypsometric tint (from Greek hypsos — height), or color relief, colours terrain by elevation above sea level. Green tones for lowlands and valleys, yellow and brown for hills and foothills, white and grey for high ridges and peaks. Everyone knows this device from a school atlas: a single glance tells plain from mountain. OSM2CDR builds color relief from the global Copernicus GLO-30 DEM with a choice of color ramp.
Color ramps
A color ramp is an "elevation → colour" lookup table. OSM2CDR offers six ready ramps:
- Soft natural (soft_terrain) — calm green-and-brown tones with no harsh steps. I keep it as the default: the terrain reads clearly without fighting the drawing that sits on top. It comes with light shading, so the terrain already looks three-dimensional.
- Topographic (topo) — the classic hypsometric scale: green → yellow → brown → white. High contrast, reads intuitively.
- Muted green (muted_green) — a restrained green range for flat areas with little elevation spread.
- Sepia (sepia) — warm brown "aged" tones for maps in a vintage look.
- Arctic — a cold palette for polar and high-mountain areas, where the usual "greenery" is out of place (no forests or meadows there). Emphasises ice, snow and rocky surfaces.
- Grayscale — shades of grey for monochrome printing, technical drawings, and cases where colour carries other meaning.
The soft natural ramp with light shading is the default; the rest are chosen in the relief settings.
Shading and hillshade
By default the elevation tint already carries light shading: colour shows absolute height, shadows show slope shape, and the map looks three-dimensional, like in big atlases. If you want stronger relief, also enable hillshade — the service multiply-blends it on top of the tint.
Global source, honest gaps
Elevations come from Copernicus DEM GLO-30 (30 m) — an open global ESA dataset covering all land including the high Arctic. Where there is no data (ocean), the raster is transparent — we do not fill emptiness with a fake colour. Flat terrain (steppe, delta) gets one or two colour bands — a truthful reflection of the relief, not a defect.
File or underlay
Like hillshade, color relief can be a standalone georeferenced GeoTIFF for GIS or a background underlay beneath the vector map when exporting to PDF/SVG/PNG. In the latter case OSM streets, buildings and labels sit on top of the colored relief — a finished topographic map in one pass.
Where it is used
- Topographic and physical-geographic maps.
- Atlases, posters, regional infographics.
- Geology, hydrology, climatology — elevation as a factor.
- Education — vivid presentation of relief.
Attribution
The relief data is Copernicus DEM. When publishing, credit: "produced using Copernicus WorldDEM-30 © DLR e.V. 2010-2014 and © Airbus Defence and Space GmbH 2014-2018 provided under COPERNICUS by the European Union and ESA; all rights reserved" — the wording is fixed by the licence.