Piano Forum

I'm sorry to state the obvious, but LOOK AT THE BLOODY THEMES! Your own analysis should be much more impressive than quotes from other people's texts; point out the themes, talk about chromatic scales then chromaticism in general. Examiners want you to prove that you are a wise musician, not a good researcher. This will aid in the way you play the piece, too, making for a much more mature performance.
After the opening two bars of the fantasia, play each note which falls on a beat (l.h quaver)from bar 7: there you find chromaticism. Look all the way through, look at the chordal/arpeggio progressions: there you find chromaticism. Think of the meaning of "chromatic", think about the relatively mercurial and *hint* COLOURFUL way in which the fantasia was written. Look at the chromatic subject of the fugue. If you really want to impress them, go on about the promotion of equal temperament which was a passion of Bach's, and the innovative use of chromaticism which was still new (due to tuning) and therefore a real shock to the ears at that time.
Basically, "Chromatic" is in the title because it is a very dominant feature of the piece; many pieces have tags due to an aural likeness to another feature, such as selected etudes by Chopin being tagged "Harp", "Sunlight" and "Winter Wind", which have been coined anonymously, and eventually become increasingly common.