Thanks for the kind words. We are always happy if our customers are happy.
To address your issue, I think you are somewhat confused. I may be missing the issue but here's a shot at clearing it up:
I understand I need to only interchange Toxic with Ice keycaps, OR Fire with Gold. No problem. Toxic and Ice are my two favorite colors anyway.
ALL of the keycaps used on the Deck Keyboards are interchangeable as long as they are the same size. The keycaps aren't the part that are colored - they are all black and white. If you are swapping them from an 82-key Deck to a 105-key Deck, the fonts may differ very slightly in size but that is the only difference (as long as the keycap itself is the same size - you wouldn't switch a CTRL key with the RETURN key because of the size difference).
You CAN switch the LEDs under the keycaps as well to make some keys blue instead of green or vice versa. An example of this can be seen on the main page of our website. At this time, it can only be done with the blue and green boards due to the electrical differences behind it (more information about that can be seen here
We also offer extra LEDs with our add-on keycap kits. Those can be found here
Hope that helps, please let us know if you need more information.