Hard Disk Monitoring

I'm looking at a partially complete disk re-initialise. Most blocks in the chart are a pale green indicating "Good". There are no yellow or red blocks.

One block is a darker green/turquoise, and a few other blocks are slightly darker than the rest.

What does this indicate please?

Thanks
Dave

The darker BLUE box is a progress indicator which shows the current block being tested.

The darker GREEN blocks indicate that the blocks are slightly lower than the other, neighbour blocks.
This is usually no problem and if some (random) blocks seem darker, completely acceptable.
Problem may occur if such darker areas form a continuous area in some parts of the drive.

Please see the Help -> Hard disk tests -> Surface test ( http://www.hdsentinel.com/help/en/61_surfacetest.html )

which describes this situation with more details and shows example images about surface map when different problems found.

Thank you
Dave