The options argument may be a mapping containing zero or more encoding options.

normal options:
"name":"xbm_image_name"
The name of the XBM. Defaults to 'image'

Supported options:
([
"fg":({fgcolor}),    // Foreground color. Default black
"bg":({bgcolor}),    // Background color. Default white
"invert":1,          // Invert the mask
])