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Someone has already asked how to randomize colors by class in QGIS new symbology, but the answer there does not work with datasets containing more than 100 unique values since the Random option only allows you to create only 100 colors. Using that technique, the features get categorized using the equal breaks method making the color the same for many consecutive features instead of assigning one per feature and then starting over with the 100 colors again after they have all been used once. My goal is to differentiate features in a polygon layer with many similarly located and named features, e.g., Woodlands 1 and Woodlands 2 are next to each other and so need to be different colors.

Is there a way to make sure that each consecutive feature is a different color from the immediately preceding and following feature? In the old symbology, you can just use "Randomize" to achieve this. Is there a way to do it in the new symbology? Thanks for any ideas or help!

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Why not just make a map of the values modulo 100? – whuber Mar 27 '13 at 21:20
I'm not sure exactly what you're suggesting... where would I do this math in the new symbology implementation within QGIS? When I say 100 is maximum, I am just picking this from a menu while trying to create a new random color ramp. I don't see any options for creating other color schemes that aren't ramps or for giving QGIS advanced instructions on how to assign the colors in the ramp. – love Apr 3 '13 at 22:27
You wouldn't use symbology: you can create a new field equal to the values modulo 100 (or modulo whatever), then symbolize its values. – whuber Apr 4 '13 at 14:51
Actually, I was looking for a way to do it with just the new symbology implementation because I don't have control of the database to add fields. So, the workaround is appreciated, but I am still wondering if there is currently a way to change this in the QGIS GUI or if I should submit a feature request. – love Apr 5 '13 at 16:06
Thanks for the clarification--it would help to include that in your question itself. – whuber Apr 5 '13 at 16:50

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