For anyone interested, I made some icon eye candy for newly created OnDemand items.
Only works if the extension in question is already loaded and then added to OnDemand.
If ImageMagick is installed, a semi transparent icon will be generated, which will be used by wbar until the OnDemand item is loaded. 
--- /tmp/core/usr/bin/ondemand
+++ /tmp/more/usr/bin/ondemand
@@ -117,6 +117,23 @@
 echo 'ondemand -e '"$EXTN"' "$@"' >> "$FILE"
 chmod +x "$FILE"
 
+if [ -e "$FREEDESKTOP"/"$APPNAME".desktop ]; then
+	FREEDESKICON="$(/bin/busybox awk 'BEGIN {FS = "="} {if ( $1 == "X-FullPathIcon" ) {icon = $2}} END {print icon}' "$FREEDESKTOP"/"$APPNAME".desktop)"
+fi
+if [ -z "$FREEDESKICON" ] && [ -e /usr/local/share/pixmaps/"$APPNAME".png ]; then
+	FREEDESKICON="/usr/local/share/pixmaps/$APPNAME.png"
+fi
+if [ -n "$FREEDESKICON" ]; then
+	#  convert  PNG to be semi-transparent via ImageMagick, if available.
+	if [ $(which convert) ]; then
+		convert "$FREEDESKICON" \
+		-alpha set -channel A -evaluate multiply 0.6 +channel \
+		/etc/sysconfig/tcedir/ondemand/"$APPNAME".img
+	else
+		cp "$FREEDESKICON" /etc/sysconfig/tcedir/ondemand/"$APPNAME".img
+	fi
+fi
+
 # Optional as flwm does not need a make_ondemand.
 [ $(which ${DESKTOP}_ondemand) ] && ${DESKTOP}_ondemand "$APPNAME"
 
Needs manual modification of  core.gz .