diff --git a/fhem/FHEM/01_FHEMWEB.pm b/fhem/FHEM/01_FHEMWEB.pm
index f8f920f17..c6e23c5c3 100755
--- a/fhem/FHEM/01_FHEMWEB.pm
+++ b/fhem/FHEM/01_FHEMWEB.pm
@@ -2050,7 +2050,7 @@ FW_makeImage(@)
       my $col = $1 if($1);
       if($col) {
         $col =~ s/@//;
-        $col = "#$col" if($col =~ m/^\d+$/);
+        $col = "#$col" if($col =~ m/^([A-F0-9]{6})$/);
         $data =~ s/fill="#000000"/fill="$col"/;
       } else {
         $data =~ s/fill="#000000"//;