Hey, ive been watching this post because i have been thinking of buying a nokia n9. I will try to address somethings i found out. Ok. I think the purple lines are called colour fringing. This is what is is.

Colored fringing around highlights or dark regions may
be due to the receptors for different
colors having differing dynamic range or sensitivity -- therefore preserving detail in one or two color channels,
while "blowing out" or failing to
register, in the other channel or
channels. (source wikipedia)

colour fringing is because of the pentile matrix.

Chromatic aberration is a lens-based
defect that occurs because the refractive
index of optical glass varies with
different wavelengths. In most optical
glass types, blue light is bent
('refracted') more than green or red light. As a result, a simple lens is unable
to bring all wavelengths of light into a
single focus point on the image plane.
There are two main types.
With longitudinal chromatic
aberration, wavelengths towards the blue end of the spectrum focus slightly
in front of the image plane and
wavelengths towards the red end of
the spectrum focus behind
it. Transverse (or lateral) chromatic
aberration occurs when the different focus points are side-shifted. In practice,
lenses affected by chromatic aberration
generally suffer from both types. It is
most common in wide angle lenses of
the retro-focus type and older tele
lenses (including zooms).

» although this is for a camera you can see the potential with amoled technologies.

Chromatic aberration manifests itself as "fringes" of color along boundaries that
separate dark and bright parts of the
image, because each color in the optical spectrum cannot be focused at a single common point. >> So you see because of the arrangement of the pentile matrix this is what happens. colour distribution is not even. I hope this makes sense? I'm typing form a mobile phone. Il have to get back with the dead pixel explanation.