Hi Priyanka,
You can update CSS like below. This will update color in alternate rows in grid.
if you want to apply to all datagrid in your application then update below code in _mxui.css
.mx-datagrid tr:nth-child(odd) {
background-color: blue;
}
.mx-datagrid tr:nth-child(even) {
background-color: red;
}
if you want to update in specific datagrid alone then add css class in datagrid appearance tab
describe the class definition in _mxui.css file like below
.oddrow tr:nth-child(odd) {background: blue}
.evenrow tr:nth-child(even) {background:red}