I am wondering what happened in the fortepiano's history that made the keyboard colors switch (why black keys on some ancient pianofortes are now white on modern pianos).

Here is a picture of a baroque fortepiano with such a keyboard.

Baroque pianoforte (taken from http://hubpages.com/entertainment/Piano-in-the-Baroque-Period) http://usercontent1.hubimg.com/8973142_f520.jpg

Did all pianofortes have this color pattern before?