Customizing Share Point 2013 Mobile Pages

I have "Mobile Browser View" enabled in my Share Point 2013 "Settings", "Site Actions".
I would like to make some minor modifications to change the (theme) header color and perhaps add a logo to the mobile view.

I have succeeded in over ridding styles in my desktop view by a adding a custom style to default.aspx, but the mobile view still has the old theme attached.

I have found some articles about revising mobile Share Point, but they seem ridiculously complex for a few simple design changes
https://msdn.microsoft.com/en-us/library/bb802539.aspx

https://msdn.microsoft.com/en-us/library/office/bb862633(v=office.14).aspx

Question:
How do you make basic css changes or add a logo to the header?

Looking at the SP server installation
c$\Program Files\Common Files\microsoft shared\Web Server Extensions\15\TEMPLATE

I am finding
MobileAdvancedStyleSheets.ascx
MobileAdvancedTemplates.ascx
MobileDefaultTemplates.ascx
MobileDefaultStylesheets.ascx

But I am not finding a basic css file, or any reference to it!

(None of the above mentioned files are found in my local copy of Share Point designer, nor can I find any related mobile templates or files)