An interesting thing about key signatures
is that at the end of the circle of fifths
keys--and the circle of fourths
keys--the Ends Battle
and Charles' Father
's write up, the sharps and flats are white
This is to be expected, though most piano students do not. It is simple arithmetic: there are seven different notes in the octave, each of which can be sharped or flatted, but only five black ones, hence E# and B# are played as F and C respectively, and Cb and Fb are played as B and E respectively.
Regardless of the colour, all notes shoud be treated the same, though most piano students, including myself, even now, cannot yet do it perfectly.