Chart gridlines are usually drawn along major categories/series values mostly to simplify values reading. Java Chart Designer gridlines dialog window allows modifying chart gridlines color, type, width and filling.
To open "Gridlines" window click "Options & Data" menu and choose "Gridlines" item or click "Options & Data" tab at Quick access panel and press "Gridlines" button.
This dialog has two tabs (Horizontal and Vertical) with identical options to modify horizontal and vertical gridlines correspondingly. Let’s us overview all available options.
"Line" checkbox toggles gridlines visibility.
"Color" control displays currently selected gridlines color. Click the button to open color selection dialog and change gridlines color.
"Type" option offers several different line types to select from: firm, dashed, dotted etc.
"Weight" spinbox defines gridlines width in pixels.
"Fill even grid area" and "Fill odd grid area" checkboxes enable (if option ticked)/disable even and odd color filling visibility correspondingly.
"Color" control displays currently selected gridlines filling color and transparency value. Click the button to open color selection dialog and change that color.