Honestly, comparing the strength of anime Goku and manga Goku is tricky. Both versions have their unique strengths and challenges depicted differently, making it hard to make a clear-cut comparison.
The majority of manga are not in color. It's a common practice in the manga industry to use black and white for regular publications. But for certain limited series or special projects, color might be employed to make them stand out.
The JoJo manga is mainly presented in black and white. However, there might be some special editions or colored illustrations for promotional purposes, but the standard version is not in color.
In general, it's a bit of a toss-up. The strength of Manga Goku and Anime Goku can vary depending on the specific arcs and battles. Sometimes, it might seem like one is stronger in a particular situation, but that could change in another.
In the manga, Goku has experienced death multiple times. However, his death is often a part of the narrative and doesn't mean the end for him. Resurrection and comebacks are common in his storyline.