What is RGB and RGBW?
LEDs consist of red, green, and blue chips. Different colors are obtained by mixing the light produced by three separate chips in certain proportions. If all three LEDs illuminate at full brightness white color obtained. Beside the red, green, and blue LED chips, there is a white LED chip in RGBW LEDs
To further that, RGB-only elements to produce whites with a cold colour temperature. When you see a "white" LED display that looks to be slightly purple, blue or green, it's generally only a 3-diode element (RGB) and incapable of producing anything close to a natural white. The CN tower's colour displays seem to be limited to RGB-only, and look pretty horrible IMO.
RGBW elements have a fourth diode (a white with a preset colour temperature) or five in the case of those with a colour-temperature adjustable white (each of a cool white and a warm white which get mixed), aka RGBWW. In any ideal situation, you'd want to go with RGBWW for as good a colour accuracy as you can get.
That said, I mean how much colour accuracy are you really looking for in a lit crown, when the standard for installations seems to be cycling a rainbow like a cheap Ikea night light?