Tunnel vision

In Annti's fantastic presentation in Amsterdam, he mentioned cool stuff that he had done for accessibility that I was not aware of.

e.g. 
for tunnel vision he had non-content parts of the screen in a dark background color to help people find the light background of the semantic content section

He had used a light gray background and not white, as it is less harsh for some user group. He also had sign translation, which is a natural and first Lang for the hearing impaired.

Can all this be incorporated into the guidelines?
Annti, could you submit some proposed checkpoints or techniques to incorporate your research?

Is there anything else that you know that we do not?

Now Before everyone flames me alive, I know that most of this is not priority one stuff. But it is things that can make the content  easer to access and should be included as P3 techniques 

 (including having  really enjoyed your presentation the in Amsterdam, and it was fun working with you.