Balala Xiao Mo Xian: Caihong Xin Shi

If you're looking for a y2k series with action, comedy, and cute girls being magical friends - both series have those a-plenty! Both casts are school students with slice-of-life episodes following their school lives. Both casts are highly unlikely friends with very different personalities and backgrounds. Balala, like SplashStar, is the first 'reboot' in a magical girl meta series, but you can start them without needing to see the previous versions.  

Cute girls are given magical powers and sent off to school to cause mischief! In Balala, they're fairies, while in Doremi they're witches. Both series have a lot of humor, with Balala's being a bit more slapstick in style. The casts are quite different and varied, but mostly in their young school years with lots of bubbly curiosity. They're also both long series, with several other seasons to binge your way through. 

Team of magical girls, each with own unusual hair color to differentiate. They transform using magical tool that is actually just a product placement toy, as the main demographic of this series is young girls. Very straight played mahou shoujo tropes. 

Team of color-coded girls that transform into special costumes using a gadget. Typical mahou-shoujo for shoujo audience, really.