I am currently creating three carbon distribution maps for three different forest management scenarios. I created a shapefile map with a 1 km x 1 km grid and computed the carbon value per pixel (per km²). Now I created the maps and noticed following problem: In scenario 1 the highest carbon value is 13, in scenario 2 the highest value is 19. However value 13 and value 19 have the same color in the different maps, because they each are the highest values in their scenario. So what I need is that one color is always applied to the same value. I am using a graduated style.

1 Answer 1


You can use the 'Categorized' type and define your own classes:

categorized colors classes

So that, they will stay fixed upon your different layers.

You can also go for some rule-based symbology if you want to fit some classes with precise intervals:

rule-based classes

These are the best way to deal with discrete classes or categories.

On the other hand, the graduated symbology is better suited for rendering a continuous phenomenon, e.g. based on its statistical distribution for example, because as you can see in the 'graduated' symbology, you can play with the histogram of your data in order to select how to apply your color map:


  • That helps alot. Thank you! Feb 22, 2021 at 19:40

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.