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This is maybe rather subjective as it concerns style, but I would like to have a few decent colour ramps for my DEM when it is layed over my hill-shading.

I have created the Swiss hillshade model as shown here, but I'm not too convinced that the colour scheme is good.

Any examples or screenshots would be great.

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6 Answers 6

up vote 9 down vote accepted

I usually come at this question from the angle of "what is going to enhance, and not obscure, my data?".

Tufte talks about the some of the uses of colours in maps: to label, to measure, to represent, and to enliven. Choosing DEM colours is usually mostly for the latter (enlivening) - to make them look nice. For example, the default 'atlas coloring' of many maps I see is really pretty (and used in the Swiss hillshade example) - it's derived from something that seems 'natural': white (snow) at the high elevations, green (forests) on the lower slopes, yellow / brown (the plains) and blue (the sea). It looks beautiful, combined with a hillshade.

However, if you apply it everywhere, you end up with map colours that are not representative - they don't reflect reality, and (worse) can be completely misleading. A Luangwa Valley map I produced once made it look like the Alps when in fact it's a deep, hot valley bounded on one side by a cool-ish escarpment (no snow, no large bodies of water anywhere).

Plus, all those colours tend not to photocopy very well, and many offices don't have colour printers where I work, so the colours all disappear or end up becoming just patches of black.

Colorbrewer is great for investigating some of the sequential colour schemes you could use on your maps. You can select 'photocopyable' and other options - but it's kind of depressing how few colours remain as you select more restrictions.

The other problem (measurement) with colour ramps is that the eye interprets divisions between shades where they don't exist – grayscale is far, far better at showing varying quantities (nice essay on this at the visual.ly blog.

So ... I almost always end up using either:

  • Grayscale hillshading, or
  • A two-colour scheme that represents the ecology or habitat of the area - often from dry (yellow or red) to wet (green).
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I think this is great,but I often take a semi-greyscale approach, but choose two colors that are faded back enough to not obscure data, but to make the hillshade seem less metallic than in many I've seen. –  nicksan May 15 '12 at 18:29
    
@Nick - Same here; I usually combine that two-colour scheme with a transparent or faded hillshade. Those metallic hillshades make everything look draped in mercury! –  Simbamangu May 16 '12 at 7:49

Expanding on one of themes in Simbamangu's very good answer: the basic problem with elevation shading using any colours at all other than neutral greys is the inescapable tendency for us to interpret meaning from the colours. For example a common rendering technique is to use deep greens for the valley bottoms, progressively lighten as one travels upslope, moving through browns and creams, to arrive finally on whites or pale blue/purple at the mountain peaks. (The technique is called hyspometric or elevation tinting.)

standard hypsometric tinting

This is very effective for conveying the shape of the terrain, lows are low and highs are high without needing to resort to interpreting contour lines. However this particular valley bottom, drawn in lush greens, may in fact be an arid-semi desert and that bare looking mountain slope at high elevation may in reality be a cloud rain forest.

The solution to counteract the tendency to misinterpret the colour values is to use a technique called Cross-blended Hypsometric Tints, excellently described by the redoubtable Tom Patterson. In cross-blended hyspometry the grey scale shaded relief provides the shade light- and dark-ness while another layer, such as classified vegetation cover, is used to provide colour values. The result is something where green really does mean vegetated and brown is rocky or barren and white is snow & ice covered, and light or dark conveys relative elevation.

Continental US in cross-blended hysp tints

So, in projects where there isn't the time or resources for cross-blending, just use grey scale.

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Natural Earth's raster download page shows a nice set of alternative views of relief, from hypsometric cross-blends to grayscale. Not sure where they get their idealised vegetation colors from, though. –  Simbamangu May 16 '12 at 7:48

First off, let me say how much I appreciate this question. I have seen so many example of inappropriate colour palettes applied to digital elevation models that it's good to see that people are thinking about this. There are some really good answers here too, but here is my opinion. I doubt that there is a universally good palette but rather a group of palettes that are appropriate for rendering elevation under different terrain and under different landscape scales. Another factor to consider is if you are planning on hillshading the DEM as well. These are my favourites:

(1) This is your standard elevation palette and is a good choice for a wide range of terrain and scales:

enter image description here

(2) When you're dealing with a slightly more mountainous terrain, you might want to have the palette start with deeper greens and end with whites. This is best if you plan on displaying a hillshade image transparently since otherwise the white may be interpreted as background.

enter image description here

(3) The following is a common palette used in atlases and I find it most appropriate for rendering smaller scales (i.e. large geographical regions).

enter image description here

(4) This palette progression is useful when you have subdued topography or when you have a lot of overlayed information and want the topography to fall into the background. It's also best when there is a hillshade image used as well.

enter image description here

(5) Finally, the following spectrum colour palette is useful when you don't want to use the typical green for valley bottom, brown for mountains relief. This may be either because you are dealing with a very large scale (e.g. a fine resolution DEM of a small area where there isn't relief at the scale of mountains) or where the DEM isn't of elevation but rather some other attribute.

enter image description here

If you are displaying the DEM transparently over a hillshade image (or vice versa) then an equally important consideration to the palette is the level of transparency. Compare the image above to the follow, both of which use the exact same palette:

enter image description here

How vibrant should the colours be compared to the hillshade tinting? It probably depends on the application (i.e. purpose of the map) and the other information that is overlayed.

You'll notice that I didn't include a greyscale image above. Here's the reason that I prefer not to render DEMs in greyscale: 1) you can't create a composite relief model (i.e. a DEM and hillshade image, as above) and 2) with all of the palettes used above people will automatically interpret them as being elevation whereas with a greyscale image, I know my immediate reaction is to interpret it as a satellite image or air photo...it takes me a moment to realize that it is in fact elevation. So unless it's an application where the map is going to be printed out (i.e. the editor has told me the figure must be greyscale) then I won't use a greyscale palette. And usually in the cases when it has to be greyscale, I'd rather use a hillshade image to convey the topography than DEM (if I have to choose one, I'll choose the hillshade).

Again, thank you for asking such a wonderful and important question!

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1  
purrty colours...! –  Joseph Aug 11 at 9:52
1  
@Joseph Sometimes it feels like I spend my day making pretty art! –  WhiteboxDev Aug 11 at 14:06

So, I use swiss hillshade for most of the maps I use (here's a screenshot from California's Central Sierra) and tend to use a red/beige-grey theme that loosely follows the philosophy that Simbamangu described of not being too in your face (ie, it's not super colorful and in some spots is even a little drab, but the information is conveyed and I can layer much more on top of it). I want the heights - at center - to pop and the flat/lowlands - at left - to fade back.

My hillshade in production

This version is a flattened GeoTiff, but the color values (all r,g,b) I use are:

  • Aerial Perspective (from this Esri toolbox): low values, white; high values, 79,79,79
  • Filtered Hillshade: low values, white; high values, 84,84,84 - layer at 35% transparency
  • DEM: low values, 255, 252,252; high values 242,220,208 - layer at 25% transparency

Legend showing range and stacking

I hope that helps show one approach. Good luck finding one that works for your map

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I follow the DEM elevation colours, and the hillshade, but what is the 'aerial perspective' layer? Really nice looking map, by the way. –  Simbamangu May 16 '12 at 7:50
    
The aerial perspective layer is part of the swiss hillshade method (blogs.esri.com/esri/arcgis/2008/10/07/updated-hillshade-toolbox) - ESRI says it "makes the higher elevations lighter and the lower elevations darker" - I think you'll need the toolbox at that link in order to create it (but I think it runs a few builtin tools, so you might be able to duplicate outside of arcmap, or without a Spatial Analyst license). –  nicksan May 17 '12 at 18:27

I think choosing a good color ramp depends on your purpose and geographic location. You can start with some examples at MappingCenter blog from ESRI

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I'm sure many people already know this, but I stumbled across an excellent source of many colour ramps for QGIS (svg format). I am using QGIS 2.4 for this.

  1. Install the plugin SVG2ColR
  2. Browse to this site: SVG Ramp

  3. Download the colour ramp you like

  4. Load the SVG colour ramp and Export as Style
  5. Settings -> Style Manager-> Color Ramp -> Share -> Import

Now you have an amazing array of color ramps. There are lots of great elevation ramps at the site I listed above. Thanks to the site owners for the excellent work!

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