diff --git a/coders/sun.c b/coders/sun.c
index 6c9286c..f3901fd 100644
--- a/coders/sun.c
+++ b/coders/sun.c
@@ -761,9 +761,7 @@
     /*
       Initialize SUN raster file header.
     */
-    if ((IssRGBColorspace(image->colorspace) == MagickFalse) &&
-        (IsRGBColorspace(image->colorspace) == MagickFalse) &&
-        (IsImageGray(image,exception) == MagickFalse))
+    if (IssRGBCompatibleColorspace(image->colorspace) == MagickFalse)
       (void) TransformImageColorspace(image,sRGBColorspace,exception);
     sun_info.magic=0x59a66a95;
     if ((image->columns != (unsigned int) image->columns) ||