One can put a condom on an 8mm or 10mm domed LED to get as close as possible to a condom on an incandescent.
It can be done to a SMD as well.
The reason for the lens not being colored, is up until a 1 SMD 5050, they reduce the light output too much, and its only purpose would to be aesthetic.....so you see color when not lit.
With newer and brighter LEDs it is now possible to color the lens, and have good brightness.
We will be releasing Purple with a purple lens and a write up soon. It took 5 or 6 revisions.
Id say 6 months, and maybe about $1K out of pocket to develop plus time.
I did so, because of the never ending emails on Purple, and it has broader use.
To do each bulb, in each color, in both bases, in all colors, is around 10K in an investment.
I will grant you, they will look nice, but with people only buying a couple for external signs, it will take
somewhere between 15-18 years to sell out initial stock, and maybe 10 years to break even.
While we may want it, and I get lots of emails to make things that are needed and wanted, it just doesnt make business sense to invest the money and time to produce.
I am not certain, but I think pinballcenter.eu may have some.