diff --git a/src/services/accessibility/html_id_generator.ts b/src/services/accessibility/html_id_generator.ts
index 483cbde9d09..21a8d80ac3b 100644
--- a/src/services/accessibility/html_id_generator.ts
+++ b/src/services/accessibility/html_id_generator.ts
@@ -7,7 +7,7 @@ import uuid from 'uuid';
  * specify it, it generates a random id prefix. If you specify a custom prefix
  * it should begin with an letter to be HTML4 compliant.
  */
-export function htmlIdGenerator(idPrefix?: string): (suffix?: string) => string {
+export function htmlIdGenerator(idPrefix?: string) {
   const prefix = idPrefix || `i${uuid.v1()}`;
   return (suffix?: string) => `${prefix}_${suffix || uuid.v1()}`;
 }
diff --git a/src/services/color/color_palette.ts b/src/services/color/color_palette.ts
index 116c32ae809..b686f9d980f 100644
--- a/src/services/color/color_palette.ts
+++ b/src/services/color/color_palette.ts
@@ -5,16 +5,10 @@ import { hexToRgb } from './hex_to_rgb';
  * Create the color object for manipulation by other functions
  */
 class Color {
-  r: number;
-  g: number;
-  b: number;
   collection: rgbDef;
   text: string;
 
-  constructor(r: number, g: number, b: number) {
-    this.r = r; // Red value
-    this.g = g; // Green value
-    this.b = b; // Blue value
+  constructor(public r: number, public g: number, public b: number) {
     this.collection = [r, g, b];
     this.text = createHex(this.collection);
   }
diff --git a/src/services/color/rgb_to_hex.test.ts b/src/services/color/rgb_to_hex.test.ts
index fc9f6954718..2875def1167 100644
--- a/src/services/color/rgb_to_hex.test.ts
+++ b/src/services/color/rgb_to_hex.test.ts
@@ -1,19 +1,50 @@
 import { rgbToHex } from './rgb_to_hex';
 
 describe('rgbToHex ', () => {
-  it('should handle rgb() without whitespace', () => {
-    expect(rgbToHex('rgb(12,34,56)')).toEqual('#0c2238');
+  describe('validation', () => {
+    it('should return an empty string for malformed input', () => {
+      expect(rgbToHex('fred')).toEqual('');
+      expect(rgbToHex('rgb(fred')).toEqual('');
+      expect(rgbToHex('rgb(fred, bob, banana')).toEqual('');
+      expect(rgbToHex('rgb(0, 3, 5')).toEqual('');
+      expect(rgbToHex('rgba(0, 3, 5')).toEqual('');
+      expect(rgbToHex('rgba(0, 3, 5, 99)')).toEqual('');
+    });
   });
 
-  it('should handle rgb() with whitespace', () => {
-    expect(rgbToHex('rgb ( 12 , 34 , 56 )')).toEqual('#0c2238');
-  });
+  describe('rgb()', () => {
+    it('should handle rgb() without whitespace', () => {
+      expect(rgbToHex('rgb(12,34,56)')).toEqual('#0c2238');
+    });
 
-  it('should handle rgba() without whitespace', () => {
-    expect(rgbToHex('rgba(12,34,56,0.4)')).toEqual('#0c2238');
+    it('should handle rgb() with whitespace', () => {
+      expect(rgbToHex('rgb ( 12 , 34 , 56 )')).toEqual('#0c2238');
+    });
   });
 
-  it('should handle rgba() with whitespace', () => {
-    expect(rgbToHex('rgba ( 12 , 34 , 56 , 0.4 )')).toEqual('#0c2238');
+  describe('rgba()', () => {
+    it('should handle no whitespace', () => {
+      expect(rgbToHex('rgba(12,34,56,0.4)')).toEqual('#0c2238');
+    });
+
+    it('should handle whitespace', () => {
+      expect(rgbToHex('rgba ( 12 , 34 , 56 , 0.4 )')).toEqual('#0c2238');
+    });
+
+    it('should handle integer maximum alpha', () => {
+      expect(rgbToHex('rgba(12,34,56,1)')).toEqual('#0c2238');
+    });
+
+    it('should handle decimal maximum alpha', () => {
+      expect(rgbToHex('rgba(12,34,56,1.00000)')).toEqual('#0c2238');
+    });
+
+    it('should handle integer zero alpha', () => {
+      expect(rgbToHex('rgba(12,34,56,0)')).toEqual('#0c2238');
+    });
+
+    it('should handle decimal zero alpha', () => {
+      expect(rgbToHex('rgba(12,34,56,0.0000)')).toEqual('#0c2238');
+    });
   });
 });
diff --git a/src/services/color/rgb_to_hex.ts b/src/services/color/rgb_to_hex.ts
index 03394726a6e..70b606f6eb5 100644
--- a/src/services/color/rgb_to_hex.ts
+++ b/src/services/color/rgb_to_hex.ts
@@ -5,7 +5,7 @@ function asHex(value: string): string {
 
 export function rgbToHex(rgb: string): string {
   const withoutWhitespace = rgb.replace(/\s+/g, '');
-  const rgbMatch = withoutWhitespace.match(/^rgba?\((\d+),(\d+),(\d+)(?:,(?:1|0\.\d+))?\)$/i);
+  const rgbMatch = withoutWhitespace.match(/^rgba?\((\d+),(\d+),(\d+)(?:,(?:1(?:\.0*)?|0(?:\.\d+)?))?\)$/i);
   if (!rgbMatch) {
     return '';
   }
diff --git a/src/services/random.ts b/src/services/random.ts
index 85dd1c78dc0..55372af35d5 100644
--- a/src/services/random.ts
+++ b/src/services/random.ts
@@ -5,33 +5,32 @@ import { times } from './utils';
 const defaultRand = Math.random;
 
 export class Random {
-  // tslint:disable-next-line:variable-name
-  _rand: () => number;
+  private readonly rand: () => number;
 
   constructor(rand = defaultRand) {
-    this._rand = rand;
+    this.rand = rand;
   }
 
   boolean = () => {
-    return this._rand() > 0.5;
+    return this.rand() > 0.5;
   }
 
   number = (options: { min?: number, max?: number } = {}) => {
     const min = isNil(options.min) ? Number.MIN_VALUE : options.min!;
     const max = isNil(options.max) ? Number.MAX_VALUE : options.max!;
-    const delta = this._rand() * (max - min);
+    const delta = this.rand() * (max - min);
     return min + delta;
   }
 
   integer = (options: { min?: number, max?: number } = {}) => {
     const min = Math.ceil(isNil(options.min) ? Number.MIN_VALUE : options.min!);
     const max = Math.floor(isNil(options.max) ? Number.MAX_VALUE : options.max!);
-    const delta = Math.floor(this._rand() * (max - min + 1));
+    const delta = Math.floor(this.rand() * (max - min + 1));
     return min + delta;
   }
 
   oneOf = <T>(values: T[]): T => {
-    return values[Math.floor(this._rand() * values.length)];
+    return values[Math.floor(this.rand() * values.length)];
   }
 
   oneToOne = <T>(values: T[], index: number): T => {