Chroma keyboard lighting issues: keys won't change color properly

I have acquired a Razer Chroma Overwatch edition keyboard here in Brazil. I am only a casual gamer, but a heavy typist, and that was the best keyboard I could find (and for the best price; discounts were huge specifically for this model). The possibility of changing key colors was also awesome, since I just hate the razer signature green hue (and I work with 3 different languages apart from English, and color customization is a big aid when dealing with a plethora of diacritics).

After just a few days, the lighting of a couple of keys simply started to fail: when I removed the keycaps, I could see that the LEDs were flickering and also they wouldn't change for some colors (e.g.: whenever I configured my keyboard for a red hue, a few keys would be stuck in a blue or green colour; same thing happened with lighting effetcs, including spectre-cycling ones). The only colors that work flawlessly are the green hues.

Razer support was very kind, and the store's service was top notch: got my keyboard replaced with no hassle at all. The new one, though, started to display the same problem a few days after using (but on different keys).

I googled it up, and saw that a couple of persons were having similar issues with their Chroma V2 keyboards. They solved the problem updating the keyboard firmware through a razer firmware updater specifically for their models (which is not mine).

How can I solve my problem? Thank you very much.