I have done experimenting with the differences between the C64 and 128.
In particular to the color articles, C128s did away with some of the color POKEs but retained others- 53280 and 53281 work on the 40-column screen, but 646 does not, and none of them work on the 80-column screen. (Poking 5328x will change the 40-column screen even when the 80-column screen is active). Extended color mode works on the 40-column screen but not the 80. Notably, the colors are changed- a simple FOR loop setting the background and/or frame color, written for the C64, will execute fine in the C128, but the colors will not match. (They do match, however, if the C128 is placed in C64 mode.)