According to a what older article at LaptopLogic NVIDIA has an idea to make the system use its integrated simpler GPU for handling day-to-day desktop graphics, while switching to the stronger and more featureful (and often more power-consuming and warmer) GPU when needed for 3D work or gaming.

Interesting idea, but with SoC designs coming from Imagination Technologies, Falanx, and other designers that reduce a GPU's power-consumption and warmth build-up you can wonder if such a design is interesting enough to work out.

After installing the latest K-Lite Codec pack and NVIDIA drivers I found that some video files had weird colours.

After some futzing around I found the issue.

Go to the NVIDIA tray icon, select color correction, at 'Apply color changes to' select 'All'. Then at 'Color profile' select 'Advanced mode' and then 'Restore Defaults', select 'Apply'. This fixed my colour problem. Apparently the new NVIDIA drivers/control panel do something with the gamma, which isn't shown in the panel.

Caused me a few days of head breaking, especially since it only was for some codecs/applications.