First of all, what's her laptop's screen? Cuz it makes a difference on what tech it's made.
Cheaper screens usually don't have such a deep colour depth that the game can display it properly.

Second of all, what are the gpu's software settings? Depending what preset she has set, be it TV, Gaming, Dayligh, etc. the colours, contrast or gamma can be set differently.
And yes, presets can be either set as global or per application. Not to mention, some settings can be set to override the application settings.

There can be multitude of causes.