themeColor property
Theme color. Possible string values are:
- "THEME_COLOR_TYPE_UNSPECIFIED" : Unspecified theme color
 - "TEXT" : Represents the primary text color
 - "BACKGROUND" : Represents the primary background color
 - "ACCENT1" : Represents the first accent color
 - "ACCENT2" : Represents the second accent color
 - "ACCENT3" : Represents the third accent color
 - "ACCENT4" : Represents the fourth accent color
 - "ACCENT5" : Represents the fifth accent color
 - "ACCENT6" : Represents the sixth accent color
 - "LINK" : Represents the color to use for hyperlinks
 
Implementation
core.String? themeColor;