The style of each level and several properties of the row group can be specified by setting RowGroup.levels. The property of each level is specified through RowGroupLevel object.
In the example below, it specifies the group header, footer and expander properties, and also specifies the height of the header and the display text separately.
grid.setOptions({
rowGroup: {
levels: [{
headerStyles: {
borderTop: null,
borderBottom: '#55',
background: "#777",
color: "#fff"
},
footerStyles: {
background: "#500088ff"
},
expanderStyles: {
borderTop: null,
borderBottom: '#55',
background: "#777",
shapeColor: "#fff"
}
},
...
]
},
...
});