Well, it's hard to say for sure. They could be related through a shared universe or a crossover event. Or perhaps they have no direct connection at all and just exist in separate manga contexts.
The JJBA manga is indeed finished. It had a great journey and wrapped up with a satisfying conclusion for fans. However, there's always the possibility of spin-offs or related works in the future.
Some popular ones could be 'Sword of the Rohan' which is known for its epic battles and complex characters. Another might be 'Rohan's Quest', a story full of mystery and adventure.
There could be multiple factors. His role models, whether they were his teachers, older siblings, or people he read about in books, might have inspired him. Also, the realization that hard work brings rewards, like good grades, praise from others, and a sense of accomplishment, would have made him keep up his hardworking attitude.
The order of JJBA manga is determined by the release dates and the development of the plot. You can start from the earliest published volume and continue in sequence to get the full story experience.
The coloring in the gappy JJBA manga can vary depending on the edition or fan-made colorings. Some are quite vibrant and true to the original style, while others might have a more unique take.