Invert site png logo on specific pages

Site URL: http://jamieodonnell.squarespace.com

Hi everyone, 

Wondering if anyone could help me to change the color of my logo on certain pages.

My home page is a portfolio page which has full bleed images so i want a white png logo as it is now.

When you click through to  portfolio page say: RETAIL this page is mostly white so the white png logo doesnt show up.
I would like the white logo to be black.

As the portfolio pages are linked to the main home page i cant find a way to invert the logo on these portfolio pages.

Here's an example of a portfolio page where it needs to be inverted:

https://jamieodonnell.squarespace.com/retail

My website link is: http://jamieodonnell.squarespace.com/
The password is: Navi1

Is there a code I can inject to simply invert it on the mostly white pages, portfolio pages, About, Contact etc?  
Or is there a way to override the logo to a different images on those pages?

Cheers.

Its ok ive sorted it out.