[R] 1-D Image as label?

[Gav Wood]

I have a data set for visualisation that comprises several sets of 1-D 
points over a given time span (the time span of the experiment). These 
are basically just several variable-length arrays of values whose units 
are seconds.

I have several sets of further data relating to the nature of the 
experiment; Each describes each second in the experiment with an RGB 
colour triplet; this amounts to a 1 dimensional bitmap image whose axis 
is the same time axis of the former data set.

I envisage one possible visualisation with the X axis (time) being 
annotated with one set of the colours from the latter data set. The Y 
axis would be either a histogram of the points from the former dataset, 
or (better, since the points are somewhat imprecise) a probability 
density function over time, derived from the gathered times themselves 
but assuming each represents an event that happened somewhere close to 
it. I am looking into using a density estimation function for this, as 
described in http://en.wikipedia.org/wiki/Density_estimation

This brings me to my question;

What would be the easiest way of annotating an axis with an array of 
colour triplets?

Thanks for any insights/information you can offer,

Gav