Thank you for the detailed feedback! ❤️
Colors are assigned the name of the nearest CSS color while still preserving their exact underlying RGB values. Because of this, two fluids can share the same name while being slightly different shades and therefore cannot connect. The exact RGB value is shown in the tooltip when hovering over a pipe, machine, or color in the Color Notebook, but I agree that the game does not explain this system clearly enough. I’m considering ways to make these differences more visible and the Color Notebook easier to understand.
Dark mode has been requested by several players as well, and I’ll consider it for a future update, although it would require some UI and readability work rather than simply changing the background.