diff --git a/core/java/com/android/internal/util/ContrastColorUtil.java b/core/java/com/android/internal/util/ContrastColorUtil.java
index 8b3c1337c0c8d..7a712e50e6a8c 100644
--- a/core/java/com/android/internal/util/ContrastColorUtil.java
+++ b/core/java/com/android/internal/util/ContrastColorUtil.java
@@ -291,10 +291,10 @@ public class ContrastColorUtil {
      * Finds a suitable color such that there's enough contrast.
      *
      * @param color the color to start searching from.
-     * @param other the color to ensure contrast against. Assumed to be lighter than {@param color}
-     * @param findFg if true, we assume {@param color} is a foreground, otherwise a background.
+     * @param other the color to ensure contrast against. Assumed to be lighter than {@code color}
+     * @param findFg if true, we assume {@code color} is a foreground, otherwise a background.
      * @param minRatio the minimum contrast ratio required.
-     * @return a color with the same hue as {@param color}, potentially darkened to meet the
+     * @return a color with the same hue as {@code color}, potentially darkened to meet the
      *          contrast ratio.
      */
     public static int findContrastColor(int color, int other, boolean findFg, double minRatio) {
@@ -331,7 +331,7 @@ public class ContrastColorUtil {
      * @param color the color to start searching from.
      * @param backgroundColor the color to ensure contrast against.
      * @param minRatio the minimum contrast ratio required.
-     * @return the same color as {@param color} with potentially modified alpha to meet contrast
+     * @return the same color as {@code color} with potentially modified alpha to meet contrast
      */
     public static int findAlphaToMeetContrast(int color, int backgroundColor, double minRatio) {
         int fg = color;
@@ -361,10 +361,10 @@ public class ContrastColorUtil {
      * Finds a suitable color such that there's enough contrast.
      *
      * @param color the color to start searching from.
-     * @param other the color to ensure contrast against. Assumed to be darker than {@param color}
-     * @param findFg if true, we assume {@param color} is a foreground, otherwise a background.
+     * @param other the color to ensure contrast against. Assumed to be darker than {@code color}
+     * @param findFg if true, we assume {@code color} is a foreground, otherwise a background.
      * @param minRatio the minimum contrast ratio required.
-     * @return a color with the same hue as {@param color}, potentially darkened to meet the
+     * @return a color with the same hue as {@code color}, potentially lightened to meet the
      *          contrast ratio.
      */
     public static int findContrastColorAgainstDark(int color, int other, boolean findFg,
@@ -393,7 +393,8 @@ public class ContrastColorUtil {
                 low = l;
             }
         }
-        return findFg ? fg : bg;
+        hsl[2] = high;
+        return ColorUtilsFromCompat.HSLToColor(hsl);
     }
 
     public static int ensureTextContrastOnBlack(int color) {
@@ -452,7 +453,7 @@ public class ContrastColorUtil {
     }
 
     /**
-     * Resolves {@param color} to an actual color if it is {@link Notification#COLOR_DEFAULT}
+     * Resolves {@code color} to an actual color if it is {@link Notification#COLOR_DEFAULT}
      */
     public static int resolveColor(Context context, int color, boolean defaultBackgroundIsDark) {
         if (color == Notification.COLOR_DEFAULT) {
diff --git a/core/tests/coretests/src/com/android/internal/util/ContrastColorUtilTest.java b/core/tests/coretests/src/com/android/internal/util/ContrastColorUtilTest.java
new file mode 100644
index 0000000000000..9da720cbfa877
--- /dev/null
+++ b/core/tests/coretests/src/com/android/internal/util/ContrastColorUtilTest.java
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package com.android.internal.util;
+
+import static androidx.core.graphics.ColorUtils.calculateContrast;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.graphics.Color;
+
+import androidx.test.filters.SmallTest;
+
+import junit.framework.TestCase;
+
+public class ContrastColorUtilTest extends TestCase {
+
+    @SmallTest
+    public void testEnsureTextContrastAgainstDark() {
+        int darkBg = 0xFF35302A;
+
+        int blueContrastColor = ContrastColorUtil.ensureTextContrast(Color.BLUE, darkBg, true);
+        assertContrastIsWithinRange(blueContrastColor, darkBg, 4.5, 4.75);
+
+        int redContrastColor = ContrastColorUtil.ensureTextContrast(Color.RED, darkBg, true);
+        assertContrastIsWithinRange(redContrastColor, darkBg, 4.5, 4.75);
+
+        final int darkGreen = 0xff008800;
+        int greenContrastColor = ContrastColorUtil.ensureTextContrast(darkGreen, darkBg, true);
+        assertContrastIsWithinRange(greenContrastColor, darkBg, 4.5, 4.75);
+
+        int grayContrastColor = ContrastColorUtil.ensureTextContrast(Color.DKGRAY, darkBg, true);
+        assertContrastIsWithinRange(grayContrastColor, darkBg, 4.5, 4.75);
+
+        int selfContrastColor = ContrastColorUtil.ensureTextContrast(darkBg, darkBg, true);
+        assertContrastIsWithinRange(selfContrastColor, darkBg, 4.5, 4.75);
+    }
+
+    @SmallTest
+    public void testEnsureTextContrastAgainstLight() {
+        int lightBg = 0xFFFFF8F2;
+
+        final int lightBlue = 0xff8888ff;
+        int blueContrastColor = ContrastColorUtil.ensureTextContrast(lightBlue, lightBg, false);
+        assertContrastIsWithinRange(blueContrastColor, lightBg, 4.5, 4.75);
+
+        int redContrastColor = ContrastColorUtil.ensureTextContrast(Color.RED, lightBg, false);
+        assertContrastIsWithinRange(redContrastColor, lightBg, 4.5, 4.75);
+
+        int greenContrastColor = ContrastColorUtil.ensureTextContrast(Color.GREEN, lightBg, false);
+        assertContrastIsWithinRange(greenContrastColor, lightBg, 4.5, 4.75);
+
+        int grayContrastColor = ContrastColorUtil.ensureTextContrast(Color.LTGRAY, lightBg, false);
+        assertContrastIsWithinRange(grayContrastColor, lightBg, 4.5, 4.75);
+
+        int selfContrastColor = ContrastColorUtil.ensureTextContrast(lightBg, lightBg, false);
+        assertContrastIsWithinRange(selfContrastColor, lightBg, 4.5, 4.75);
+    }
+
+    private void assertContrastIsWithinRange(int foreground, int background,
+            double minContrast, double maxContrast) {
+        assertContrastIsAtLeast(foreground, background, minContrast);
+        assertContrastIsAtMost(foreground, background, maxContrast);
+    }
+
+    private void assertContrastIsAtLeast(int foreground, int background, double minContrast) {
+        try {
+            assertThat(calculateContrast(foreground, background)).isAtLeast(minContrast);
+        } catch (AssertionError e) {
+            throw new AssertionError(
+                    String.format("Insufficient contrast: foreground=#%08x background=#%08x",
+                            foreground, background), e);
+        }
+    }
+
+    private void assertContrastIsAtMost(int foreground, int background, double maxContrast) {
+        try {
+            assertThat(calculateContrast(foreground, background)).isAtMost(maxContrast);
+        } catch (AssertionError e) {
+            throw new AssertionError(
+                    String.format("Excessive contrast: foreground=#%08x background=#%08x",
+                            foreground, background), e);
+        }
+    }
+
+}