GraphTheme to the theme prop. The value is deep-merged with DEFAULT_THEME, so you only override what you care about.
Theme reference
theme.node
theme.node
theme.link
theme.link
theme.edge
theme.edge
theme.label
theme.label
theme.hover
theme.hover
theme.force
theme.force
theme.cluster
theme.cluster
theme.click / theme.edgeClick
theme.click / theme.edgeClick
theme.fontFamily
theme.fontFamily
CSS variables
The package only styles the container and the optional zoom indicator — everything inside the canvas is painted from the theme. Override on.cg-root.
The zoom indicator picks up
cg-zoom-label--{position} modifier classes — override any of them in your own CSS to retarget placement.