... The logo is different and the cream colour on the bag should be black xD! ...
Your bag looks good, Emma, but the logo is wrong, too. It's the older one from the 70s.

The 80s logo patch of the screen used bag has a large orange globe without coordinates (N, W and S) and italic letters without a hyphen between EAST and PAK (
EASTPAK). Here's a screen cap of the scene where Marty and Jennifer are standing in front of the school door:
Four weeks ago, I bought a backpack on eBay. It has the correct colors and shape and the logo patch seems to be correct, too. I'm still waiting for the delivery, but here are the eBay images:
