Well, Webtoon is quite popular. It offers various genres of manga and often updates with new content. Also, it has some unique features like community interaction.
Mangatoon is worth trying. It has a decent collection and provides a smooth reading experience. Some of its features like bookmarks and recommendations are quite handy.
Tachiyomi could be what you're looking for. It's customizable and has a lot of sources for free manga. However, it might require a bit of setup to get it working just right.
You might have luck finding colored manga on dedicated manga apps such as Comixology or Crunchyroll Manga. Sometimes, social media groups or forums focused on manga can also point you in the right direction to access colored manga.
There are indeed apps for manga reading. For example, MangaZone and Crunchyroll Manga provide access to various manga titles. However, the availability might depend on your region and device compatibility.
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.