Colours

The world is full of many hues,
Not just reds and greens and blues,
Yellow, purple black and white,
But millions which show in our sight.
We can detect a tiny change
In the colours in each range;
The slightest variation leads
To a shade, from which proceeds
In tiny steps until at last,
Another well known colour's passed.
Reds turn slowly into browns,
As black their vibrant colour drowns;
Reds and whites turn into pink,
As together both shades sink;
Blues and yellows turn to green,
With many changes in between.
The normal human eye can see
Two million shades; most would agree
That's huge, and; no computer can
Compete on this with any man.