The "RT" spectacles would work in a similar way to Polaroid sunglasses, but they'd have a reverse effect in sunlight with the tint fading (as sunlight of course has a positive effect in itself and too much positivity could be highly dangerous - unless of course you work in Los Angeles).
In the winter, the tint would become stronger to counter the winter blues.
Clearly the first licences to be granted would be for spectacles and glasses, the plan being to cover all areas of distribution and for the product to appeal to all demographics. Each manufacturer would have to go through a stringent pitching process to be become an official "RT" spectacle supplier. They would be actively encouraged to wear samples, in particular when considering royalties and guarantees payable. Upon winning the licence, the licensee would then be supplied with liquid rose tint, for use in their manufacturing process. There would obviously be a contact lens version with rose-tinted eyewash and saline solution too.
Another area that could utilise the "rose tint" technology is the workplace.
Imagine glass offices with rose-tinted windows and workspaces with rose-tinted glass petitions. It would be an environment that would create a highly motivated and productive workforce. Of course, Clarke Industries would look to license this technology to office builders, and receive a royalty from the landlord for revenues earned.
Markets would continue to expand, targeting many new areas including retailers' shop windows, customer service windows - the list is endless and the future of rose- tinted spectacles looks, well, remarkably rosy.