>Simple is nice. I took your advise, Green for ascending, Red for Descending, Dark Gray for index not used and white for no index available.
>
>Thanks!

If you want to avoid the colours. I set the header's caption Italic if a column has an index. If the column is sortet I set the font in the header to bold. To indicate the sort order I prepend the caption with a string as follows

#define	_ASC_	'^ '
#define	_DESC_	'v '