Delta defines width painted by the same colour.
ASCAN's Hipsometry Dialog:
Edit Delta
key-in:
ascan hipsometry delta number
If for example delta = 0.01 then points with elevation between 0.00 and 0.01 have color from first item in color table (usually blue).
In this case it is possible to paint 255x0.01 = 2.55 units and points at distance between 2.54 and 2.55 will have last item in color table (usually brown).