Color Blindness by OKViz is a tiny library to use in Power BI custom visuals. It allows to apply different color visions to any visual that implement it.

For more information about color blindness, see our post at https://okviz.com/color-blindness/

Here is a step-by-step guide to implement the library:

1. Create a new custom visual or load an existing one. Note that if you never developed a custom visual before, you should read the Microsoft official documentation at https://github.com/Microsoft/PowerBI-visuals.

2. Copy the colorblind.ts file into your src folder.

3. Open the tsconfig.json file and append the following string to “files” section:

   "src/colorblind.ts",

4. Open the capabilities.json file and edit the “objects” section as described below:

   "objects": {
       //... (all the other visual properties here),
       
       "colorBlind": {
           "displayName": "Color Blindness by OKViz",
           "properties": {
               "vision": {
                   "displayName": "Vision",
                   "type": {
                           "enumeration": [
                           {
                               "displayName": "Normal",
                               "value": "Normal"
                           },
                               {
                               "displayName": "Protanopia",
                               "value": "Protanopia"
                           },
                               {
                               "displayName": "Protanomaly",
                               "value": "Protanomaly"
                           },
                               {
                               "displayName": "Deuteranopia",
                               "value": "Deuteranopia"
                           },
                               {
                               "displayName": "Deuteranomaly",
                               "value": "Deuteranomaly"
                           },
                           {
                               "displayName": "Tritanopia",
                               "value": "Tritanopia"
                           },
                           {
                               "displayName": "Tritanomaly",
                               "value": "Tritanomaly"
                           },
                           {
                               "displayName": "Achromatopsia",
                               "value": "Achromatopsia"
                           },
                           {
                               "displayName": "Achromatomaly",
                               "value": "Achromatomaly"
                           },
                           {
                               "displayName": "Low Contrast",
                               "value": "LowContrast"
                           }
                           ]
                       }
               }
           }
       }
   },

5. Create two properties in your iVisual class:

   private element: d3.Selection<HTMLElement>;
   private vision: string;

6. Append this code in the constructor() function:

   this.element = d3.select(options.element);
   this.vision = "Normal";

7. Append this code at the end of the update() function:

   if (options.dataViews && options.dataViews[0] && options.dataViews[0].metadata && options.dataViews[0].metadata.objects) {
       let colorBlindObj = options.dataViews[0].metadata.objects ["colorBlind"];
       if (colorBlindObj) {
           let vision = <string>colorBlindObj["vision"];
           if (vision !== undefined) {
               this.vision = vision;
           }
       }
   }
   
   OKVizUtility.applyColorBlindVision(this.vision, this.element);

8. Edit the code of the enumerateObjectInstances() function as described below:

   let objectName = options.objectName;
   let objectEnumeration: VisualObjectInstance[] = [];
   
   switch(objectName) {
   
       //… (all the other visual properties here),
   
       case "colorBlind":
                       
               objectEnumeration.push({
                   objectName: objectName,
                       properties: {
                           "vision": this.vision
                       },
                       selector: null
               });
               break;
   }
   return objectEnumeration;

9. You’re done, enjoy!

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See the LICENSE file for license rights and limitations (MIT).