There's an interesting Wired article, about how teams at Philips struggled to come up with the optimum filter. IIRC, at some point they were using some type of gel to 'tint' the LED light to resemble an incandescent bulb.
Of course, nearly all of this has probably flown out the window, because the bulbs are so cheap now. (The Wired article was from over a decade ago.)
There's an interesting Wired article, about how teams at Philips struggled to come up with the optimum filter. IIRC, at some point they were using some type of gel to 'tint' the LED light to resemble an incandescent bulb.
Of course, nearly all of this has probably flown out the window, because the bulbs are so cheap now. (The Wired article was from over a decade ago.)