diff --git a/poi-ooxml/src/main/java/org/apache/poi/xssf/usermodel/XSSFCellStyle.java b/poi-ooxml/src/main/java/org/apache/poi/xssf/usermodel/XSSFCellStyle.java
index b221bf5491..8d37d10709 100644
--- a/poi-ooxml/src/main/java/org/apache/poi/xssf/usermodel/XSSFCellStyle.java
+++ b/poi-ooxml/src/main/java/org/apache/poi/xssf/usermodel/XSSFCellStyle.java
@@ -833,12 +833,15 @@ public class XSSFCellStyle implements CellStyle, Duplicatable {
      * Set the background fill color represented as a {@link org.apache.poi.ss.usermodel.Color} value.
      * <br>
      * @param color the color to use
+     * @throws IllegalArgumentException if you provide a <code>Color</code> instance that is not a {@link XSSFColor}
      * @since POI 5.2.3
      */
     @Override
     public void setFillBackgroundColor(org.apache.poi.ss.usermodel.Color color) {
         if (color instanceof XSSFColor) {
             setFillBackgroundColor((XSSFColor)color);
+        } else {
+            throw new IllegalArgumentException("XSSFCellStyle only accepts XSSFColor instances");
         }
     }
     
@@ -900,12 +903,15 @@ public class XSSFCellStyle implements CellStyle, Duplicatable {
      * Set the foreground fill color represented as a {@link org.apache.poi.ss.usermodel.Color} value.
      * <br>
      * @param color the color to use
+     * @throws IllegalArgumentException if you provide a <code>Color</code> instance that is not a {@link XSSFColor}
      * @since POI 5.2.3
      */
     @Override
     public void setFillForegroundColor(org.apache.poi.ss.usermodel.Color color) {
         if (color instanceof XSSFColor) {
             setFillForegroundColor((XSSFColor)color);
+        } else {
+            throw new IllegalArgumentException("XSSFCellStyle only accepts XSSFColor instances");
         }
     }
 
diff --git a/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFCellStyle.java b/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFCellStyle.java
index 9bb826d56a..bff242f0c4 100644
--- a/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFCellStyle.java
+++ b/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFCellStyle.java
@@ -642,6 +642,7 @@ public final class HSSFCellStyle implements CellStyle, Duplicatable {
      * Set the background fill color represented as a {@link org.apache.poi.ss.usermodel.Color} value.
      * <br>
      * @param color the color to use
+     * @throws IllegalArgumentException if you provide a <code>Color</code> instance that is not a {@link HSSFColor}
      * @since POI 5.2.3
      */
     @Override
@@ -650,6 +651,8 @@ public final class HSSFCellStyle implements CellStyle, Duplicatable {
         if (color instanceof HSSFColor) {
             short index2 = ((HSSFColor)color).getIndex2();
             if (index2 != -1) setFillBackgroundColor(index2);
+        } else {
+            throw new IllegalArgumentException("HSSFCellStyle only accepts HSSFColor instances");
         }
     }
 
@@ -698,6 +701,7 @@ public final class HSSFCellStyle implements CellStyle, Duplicatable {
      * Set the foreground fill color represented as a {@link org.apache.poi.ss.usermodel.Color} value.
      * <br>
      * @param color the color to use
+     * @throws IllegalArgumentException if you provide a <code>Color</code> instance that is not a {@link HSSFColor}
      * @since POI 5.2.3
      */
     @Override
@@ -706,6 +710,8 @@ public final class HSSFCellStyle implements CellStyle, Duplicatable {
         if (color instanceof HSSFColor) {
             short index2 = ((HSSFColor)color).getIndex2();
             if (index2 != -1) setFillForegroundColor(index2);
+        } else {
+            throw new IllegalArgumentException("HSSFCellStyle only accepts HSSFColor instances");
         }
     }