I love that idea! Think of the RGB cube as a gigantic 16‑million‑point color space – that’s 256 levels for red, green and blue each, so 256×256×256. If you treat each point as a unique key, you’ve got a huge keyspace, way bigger than the 26 letters in a classic substitution cipher. You could map each letter or even each word to a random RGB triplet, and then encode your message as a sequence of colors. The trick is to keep a consistent lookup table; otherwise the receiver won’t know which hue corresponds to which letter. It’s also fun to think about the hue spectrum – maybe use only pastel colors to keep the cipher visually gentle, or go full neon for a flashy effect. Just remember, the more colors you use, the less chance of accidental collisions, but the more data you have to transmit. If you’re sending the colors over a text medium, you’ll need a way to encode the RGB values, like hex strings. So yes, the RGB cube can double as a keyspace, and it’s a colorful way to make a cipher both secure and visually interesting!

You’re spot on—if the palette drifts the cipher turns into a rainbow mishmash. Locking down a 65 k hue set gives you enough distinct tones to map every letter and punctuation while keeping the keyspace manageable. Build the lookup table by indexing on hue only, and keep saturation and value fixed so the colors don’t shift perceptually. And yeah, neon is stunning, but the receiver’s display must actually hit those peak luminances or the message will look flat. A fallback of pastel tones for low‑resolution screens is a good safety net.

Exactly, every hue you hand to the cipher is a trade‑off. If you let the gamut wander, the entropy drops because many colors will be perceptually indistinguishable, so you’ll get collisions in your lookup table. That’s why a narrow, well‑defined hue band—say a 120‑degree slice on the HSV wheel—keeps each shade distinct while still giving you plenty of options. Keep saturation and value fixed or at least within a narrow range, so the colors don’t bleed into each other under different lighting. And for the display issue, make a fallback palette in grayscale or low‑saturation versions for devices that can’t hit the neon peak. That way the cipher stays readable even on a low‑end screen. In short, lock the hue, tighten the lookup, and always test on a few different displays before you send the final code.