about 3D contents development using the unity.

Can I use the unity to develop the following 3D content?
The color should be reflected in real time.

Absolutely. Yes.

Out of the box, unity does not provide any AR tools, however there are some out there (I can vouch for Vuforia being a very solid product from my experience).

Based on the footage here the colour is unlikely to be a realtime change as such, If you pay attention at around 1:00, 1:07 (there are some more examples but those 2 are fine) in the footage, the users are focusing on the page as a whole this is likely to give the AR solution an opportunity to detect the known image pattern, then use the rest of the camera image to generate a texture for the 3D content that is then anchored to that AR marker.

So to break it down. Yes with an AR package it would likely be done as follows (as a hugely broad overview).

  • Image sheets are known image targets.
  • User colours image then uses the app to take a picture (more or less) of the sheet.
  • AR package locates the marker position/orientation in the image.
  • Use that known data to then extract parts of the image onto a texture for your models materials.
  • Display appropriate content based on the target image with the generated materials.

It’s not a simple thing to do by any means, and I’ve not done anything this complex in AR before, but this would be my best guess as to how this is achieved, and hopefully points you down the right route.