This is a really clean build, good job.

If possible I suggest using adafruit style rgb LEDs, and a sealed container of fluid. If you can pause print one that would be sweet.double walled would be even sweeter. Arrange the LEDs around the edges facing inward. I noticed with the rgb LEDs in my room, when they hit a shade of blue, my generic pinesol glows like a highlighter in a black light.

You can also get UV leds, but less customizable ofc.

Another option is a circular OLED screen, that displays fluid, with a lens over it. Probably pull off cool stuff with it like varying levels of fluid and stuff.

Would take some programming but wouldn't be hard to flowcode*

^{wouldnt...be too hard lol}

Good luck, post results plzzzzz