Style sheets
A style sheet contains a complete definition for a mind map’s appearance. It defines a color scheme and sub-styles for topics and relations. SimpleMind has a set of good looking built-in style sheets to quickly change the look of your mind map. When you switch to Dark Mode the built-in style sheets will also switch to Dark Mode.
Download more stylesheets here or create custom style sheets.
To select a style sheet:
Mac and Windows: Click the style sheet icon 
in the toolbar.
iPad/iPhone and Android: Tap on the style sheet icon or select “Style Sheet” from the overflow menu.
Create custom style sheets
Create your own custom style sheet to suit your needs perfectly. Change colors, line styles, topics, crosslinks and more. Create a custom style sheet by first selecting one that resembles it.
Windows: Click the style sheet icon in the toolbar.
Next click the "Edit" icon. Customize and click "save" or "save as".
Mac: Click the style sheet icon in the toolbar.
Click "Edit" so that turns blue and next click the edit icon to the left of it. Customize and click "save" or "save as".
.
iPad/iPhone: Tap from the toolbar or tap “Style Sheet”. Tap "Edit". Select a style sheet. Tap the "edit style" icon at the bottom. Name the style sheet, customize and tap "Save".
Android: Tap the style sheet tool from the toolbar or “Select Style Sheet” from the overflow menu. Tap action bar next to the style sheet and tap [+]. Name the style sheet, customize and tap "OK".