Yes, it’s possible. Here’s a full list of the properties to customize grid lines and tick marks:
tickMarks – object describing the tick marks properties of the valueAxis
visible – true/false/’custom’ determining the visibility. When ‘custom’ is set, displays only custom values/offsets.
step – interval steps between tick mark placements.
dashStyle – tick marks dash style, e.g. ‘2,2’,
lineWidth – line width in pixels of the tick marks.
size – size in pixels of the tick marks. The default is 4.
color – color of the tick marks, e.g. ‘#757575′.
custom – an array of custom values/offsets where a label/tickmark/gridline will be displayed.
gridLines – object describing the grid lines properties of the valueAxis
visible – true/false/’custom’ determining the visibility. When ‘custom’ is set, displays only custom values/offsets.
step – interval steps between grid line placements.
dashStyle – grid lines dash style, e.g. ‘2,2’,
lineWidth – line width in pixels of the grid lines.
color – color of the tick marks, e.g. ‘#757575’.
custom – an array of custom values/offsets where a label/tickmark/gridline will be displayed.