There was a difference between the PTE livery and the post deregulation Busways era. Tyne and Wear P.T.E basically ceased to be on October 26, 1986 when deregulation happened. In the previous years in the run up to dereg many buses and trains (incl. Metro of course) operating in Tyne and Wear were painted in the yellow/white PTE livery. This included not only Tyne and Wear PTE, (it became Busways) but also United Automobile Services (It became Northumbria and now Arriva) and Northern General Transport (now Go Ahead) and the local train services on the Newcastle - Sunderland line, maybe other lines as well subject to diagrams, when the 143's were introduced.
After deregulation the PTE was renamed "PTE Buses" in the interim period complete with stickers on the side over the PTE logo, before Busways started. When Busways started there was a different colour scheme applied to the buses to denote their region. This was in the form of a thick coloured line down the side above the lower deck windows and on the bottom skirt panels. (Maybe a pinstripe below the lower deck windows as well - can't remember). Newcastle Busways (Slatyford) and City Busways (Byker) were maroon, not red, and as mentioned Shields was blue and Sunderland (both Hylton Rd & Fulwell depots) was green. The destination blinds also had a colour to match the livery. Never liked that bit but Eric Hutchison did and he was the boss so that was that...Even the wheels were painted in the particular colour, maroon/blue/green etc in keeping with the colour scheme of the area.
The PTE yellow/white scheme was varied over many years and at one stage included a yellow/cream scheme which was flipping awful. The bottom bit below the lower deck windows was yellow, the rest up was cream. Yuck.
I worked for the PTE, then Busways from '82-'94 and saw a few changes. Still miss the yellow buses though.
Loads of photos here
http://www.nebptwpte.fpic.co.uk/ and here
http://ian-hignett.fotopic.net/c151249.html and no doubt other places as well.