Strikethough text and changing colour

[Damian McGuckin]

I went back to a posting from 10 Nov 2002 where Greg Leahy responded to 
Larry McVoy and suggested:

.de overstrike
.nr width \w'\\$1'
\\$1\v'-.25v'\h'address@hidden@u'\l'address@hidden@u'\v'.25v'
..

For striking out text, as in

        .overstrike old
        new

It does not work for me.

Also, how do I change the colour of text please?

Thanks - Damian