##If Some People Really Can't See It, It Needs To Be More Visible
If 1 in 20 people coming to the site to get help can't see the button they have to click to get help, that would make this an extremely serious bug.
We don't have to break the aesthetic feel of the site to change this. We can give the text itself more contrast. We could even have a notification bar appear at the top of the screen for new users (well, I think we could do this) reminding them that:
Questions should be asked as questions. Answers should be posted as answers. (I'm not saying we should word it quite like that!)
You can ask a question by pressing that button. When the user hovers the mouse pointer over the notification, the Ask Question button is highlighted.
In effect, this would achieve all the positive effects, and none of the negative effects, of actually having a green hand-drawn circle around the Ask Question button. ;-)
While decisions about this should be made to make the site accessible to users, that would not be the only benefit. Questions posted as answers constitute a substantial commenting and flagging load on users, and the workload for moderators to deal with all these flags is probably rather formidable too.
Finally, we should find out if the Ask Question button, as it is now, is specifically inaccessible to people with certain disabilities. It is critically important that we not conclude it's fine as it is, at least until we have satisfied ourselves that we're not discriminating against people with visual impairments.