Thanks for the detailed explanation of what you know. Please explain (mock-up) what it is you are looking for. Thx!
You may want to try coding a calculation to allow 2 discrete options from your measures map. (i.e. Above a certain # or below a certain #.)
And then just pick the colors you want based on the three colors you hope to see on the 'Muddy Map'. That should provide you a three color final map.
I agree with John. You're really not looking for a continuous color, you are looking for a 3-color dimension: Red, Blue, Purple, which can be created by a calculated field. But if you are also looking to 'control' or 'affect' the intensity of the color, then (as far as I know) Tableau does not support this sort of combination of discrete & continuous colors; at least without getting what you consider 'muddy'.
The best one could usually do is
colouring your Measure Map in shades of Grey,
and setting both maps Transparency as needed.
But if one strives for perfection and demands vivid colours,
there's no way other than making Data Blend
using a hand-made "Scaffold" Primary datasource
comprised of all Dimensions necessary for a map view,
including the hard-coded Sales Bins.
Please find the attached.
Hope it could help a bit.
I've got a solution that will get vivid colors, I'm doing a writeup on it that will be ready on Monday.
1 of 1 people found this helpful
Here you go... I created an ad hoc group of red states & blue states and then colored each set of them by the % of Total Sales where the lightness of the two color ramps is symmetrical so we can accurately compare across red & blue.
I documented several methods for this sort of coloring, there are two that can exactly achieve this result, and did a big writeup on this. See Two Sequential Color Palettes on the Same Map: Coloring by a Dimension and a Measure | Drawing with Numbers, here's a link to the workbook: Two Sequential Palettes on a Map.