diff --git a/color/color-common.ts b/color/color-common.ts
index 0de2a470c..2772a5515 100644
--- a/color/color-common.ts
+++ b/color/color-common.ts
@@ -94,6 +94,12 @@ export class Color implements definition.Color {
     }
 
     public static equals(value1: definition.Color, value2: definition.Color): boolean {
+        // both values are falsy
+        if (!value1 && !value2) {
+            return true;
+        }
+
+        // only one is falsy
         if (!value1 || !value2) {
             return false;
         }
diff --git a/ui/styling/font-common.ts b/ui/styling/font-common.ts
index 20454269f..a5c9604e6 100644
--- a/ui/styling/font-common.ts
+++ b/ui/styling/font-common.ts
@@ -84,6 +84,16 @@ export class Font implements definitios.Font {
     }
 
     public static equals(value1: Font, value2: Font): boolean {
+        // both values are falsy
+        if (!value1 && !value2) {
+            return true;
+        }
+
+        // only one is falsy
+        if (!value1 || !value2) {
+            return false;
+        }
+
         return value1.fontFamily === value2.fontFamily &&
             value1.fontSize === value2.fontSize &&
             value1.fontStyle === value2.fontStyle &&