add custom scale

projects/nshmp-apps/src/app/designmaps/rtgm/services/app.service.ts

@@ -300,8 +300,23 @@ export class AppService
     }
   }
 
-  private colorScale(): readonly string[] {
-    return d3Color.schemeGnBu[9].slice(3, 8);
+  private colorScale(iterations: RtgmIteration[]): readonly string[] {
+    const ncolor = iterations.length % 9;
+
+    const colors: (readonly string[])[] = [
+      [],
+      ['#084081'],
+      ['#2b8cbe', '#084081'],
+      ['#7bccc4', '#2b8cbe', '#084081'],
+      ['#ccebc5', '#7bccc4', '#2b8cbe', '#084081'],
+      ['#f7fcf0', '#ccebc5', '#7bccc4', '#2b8cbe', '#084081'],
+      d3Color.schemeGnBu[6],
+      d3Color.schemeGnBu[7],
+      d3Color.schemeGnBu[8],
+      d3Color.schemeGnBu[9],
+    ];
+
+    return colors[ncolor];
   }
 
   private createDerivativeFragilityPlot(
@@ -354,7 +369,7 @@ export class AppService
     yRange: number[]
   ): Partial<PlotData>[] {
     const fragilitySlices: Partial<PlotData>[] = [];
-    const colors = this.colorScale();
+    const colors = this.colorScale(iterations);
 
     iterations.forEach((iteration, index) => {
       const color = colors[index % iterations.length];
@@ -466,7 +481,7 @@ export class AppService
     const hazardFragilityPlotData: Partial<PlotData>[] = [];
     const integralHazardFragilityPlotData: Partial<PlotData>[] = [];
 
-    const colors = this.colorScale();
+    const colors = this.colorScale(iterations);
 
     iterations.forEach((iteration, index) => {
       const color = colors[index % iterations.length];