Color emphasis lets you create a grid with finer lines for more precise plotting. To use color emphasis, unlock the Color Palettes feature through In-App Purchases. With unlimited Color Palettes, you can select one of the pre-set color palettes or set up your own custom color ranges.
2 CUSTOMIZE SETTINGS
NEXT — We need to visit the different grid levels - starting at the finest (Subdivision level) first.
3 TWEAK GENERAL SETTINGS TO FINISH
That's how to use color to provide just the right differentiation between the lines in your graph.