The Bleach manga is not colored. It's common for manga to be in black and white to focus on the line art and storytelling. Color versions might exist in certain promotions or adaptations, but the core manga is monochrome.
The JoJo manga is mainly in black and white. Colored versions exist but are not the norm. Sometimes, colored illustrations are done for promotional purposes or by fans.
Generally, manga are black and white. This is mainly due to cost and production time constraints. However, some popular series might have colored pages for special chapters or volumes.
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.
You can search for colored manga on specialized manga websites or platforms. Some artists or groups might upload colored versions of popular manga there.