I just listed empty colored capsules on Ebay. I have no idea of what the value is, so I listed them with Buy it now or best offer. I added the link to my ebay.
https://www.ebay.com/sch/various4u/m.html?item=142479712137&hash=item212c73df89%3Ag%3AkOsAAOSwmClZlt3H&rt=nc&_trksid=p2047675.l2562