The color metallic silvery green might represent a magical object or creature. For example, it could be the color of a rare magical plant that has special powers. Maybe it's the hue of a mysterious potion that glows with that color when brewed correctly.
I have no idea. But you might try searching on specialized manga websites or asking in manga communities to see if anyone knows about a Metallic Rouge manga.
You can achieve a metallic color effect in comics by using special shading techniques and a combination of colors like silver, gold, and bronze. Experiment with light and shadow to give it a realistic look.
One of the common themes is rivalry. Since they are both involved in the same kind of activities, their competitive nature towards each other is often depicted. Also, the theme of mentorship can be seen sometimes, with Ryuga being a sort of mentor to Kenta in some fanfictions.
In some science fiction, metallic hydrogen is often depicted as a super - powerful energy source. For example, it might be used to power advanced spaceships that can travel vast distances across the galaxy at incredible speeds.
I don't think I've heard of a metallic rouge manga. It could be a self-published or indie work that's not widely known. You might have better luck finding information on specific manga platforms or through manga collectors.
One common theme is rivalry - turned - friendship. In the original Beyblade series, Ryuga and Kyoya are rivals, and in fanfiction, this often evolves into a deeper relationship. Another theme is the power struggle. They both are strong bladers, so stories might explore how they balance their power and how it affects their relationship.
One popular ryuga and kenta fanfiction is 'The Bond of Ryuga and Kenta'. It focuses on their friendship and the adventures they go through together. Another one might be 'Ryuga's Influence on Kenta', which shows how Ryuga's actions and character shape Kenta's growth in the story.