Well, DBZ coloured manga stands out for its bold color choices that bring the action scenes to life. Also, the colors help emphasize the emotions and powers of the characters. The overall effect is very immersive.
I'd suggest looking on platforms like Comixology or Kindle. They often have a wide range of manga available for purchase and reading. Just make sure to check the availability of Bleach specifically. Also, some fan-run forums might have links, but be cautious as these could be against the law and of poor quality.
In my opinion, both have their merits. The anime brings the characters to life with animation and sound, but the manga allows for more imagination and detail in the panels. It really comes down to what you value more in your entertainment.