The eye has always been red, but this new design is still relatively new, and I was speaking in terms of the new animated Cyborg design.
If we are talking about the predominantly silver Cyborg look than sure red works. But if you throw in some black etc, another primary color helps out. Too much red is just overly aggressive to me.
I just don't see the color red being that integral to the character as your making it come off as.
An unbalanced amount of red just doesn't look good to me, Say for example the current Teen Titans team:
this team desperately needs another primary color. One of the things I love about Justice League is that the team has a very diverse amount of bright primary colors in the group. Unless a book or character is suppose to be dark and moody and characters need to fit the tone of that book (like Batman), I like heroes to be bright and colorful.
I think red works with the current comic design we see, but the blue color scheme suites this animated design nicely
Bookmarks