5high on "why do my page titles change colour on smaller screen?"

I've just noticed that all my page and post titles and subtitles change colour when the browser is reduced to the smaller screen size. They're usually red (for .entry-header .entry-title and.entry-content h3) but then they change to grey, and show that they've been changed to 'body' too.
site is here: http://www.trevorpenfold.com
I realise it must be something to do with the mobile settings, but i can't find where to change it in the Twenty Twelve theme (for my 2012 child theme).
Any ideas? Or is this standard practice for mobile settings?
Thanks...