They've had colored contacts since waaaaaaaay before Den-O came about, though iirc you still need a prescription for them. I've been considering getting purple though. :anime:
I'd love to have them too, I know I had a site saved that actually sold {albeit expensively} custom contacts..they had a lot, the only one I remember though are the Naruto like ones. Those were weird.
but with everyday colored contacts, I just wonder how good they'd show on Brown eyes...;-/
I do. If you notice some of the head-turns and zoom/pan shots in the original series you can see where they missed the effect (I'm thinking in particular of a shot of U-Ryotaro) or where Takeru's eyes were too small in the frame to overlay. I admit that mb Ryota or Masahiro wore contacts but I don't think Kanna did. Even so they were almost certainly augmented with CGI.\
In a side note, I really wish that Ryutaros had possessed Daiki. They seem similar to me, in personality.
I know at http://www.9mmsfx.com/ they make custom lenses and even lenses without pupils.. (but if you have a lens without pupils it means you wont be able to see..)
They do contacts for many movies and theatre stuff so.. it's a pretty reliable site. Like they are most likely to really show up on dark eyes..
downside is that they're kinda expensive.