Provided the colours you require change based on layer then it is possible.
If all eight (or more than 4) print on the same layer then no.
I have written about this and given examples of my own models and print profiles where I used this.
It is possible with the AMS and the AMS lite.
Since then, I have uploaded other models that use the technique.
This one uses it for a couple of the profiles.
The idea is to tell the model it will print with four colours, but, you selectively remove and replace the filament ps with like types, with a different colour when required, often using the PAUSE at layer command to give yourself time to swap the filaments out.
If the colour choices in the models are simple, for example four colours in the bottom half and four different colours in the top half, then a single pause is required.
The more complex the changes, the more you may need the PAUSE command to assist you.
Make sure you read everything in the first link and the associated links within it as they give lots of instructions of how this works. Including the print profiles.
Read the text on the PAUSE print profiles to see how the second link works.