#2 Disc extends too far down/right

[Tom Lee]

It's not noticeable (even viewed pixel by pixel with
xmag or the like) in the standalone version, but in the
panel applet version, the disc seems to be slightly
closer to the bottom and right sides of the color wheel
than to the top and left sides. I've decreased the
size of the disc by one pixel in each direction, which
has improved the problem, but it needs further looking
at. Another pixel ...? Move it up and to the left by
one ...? How would this affect the standalone version?