The web viewer ships with a set of visual themes and configurable appearance options. This example changes the viewer's theme and background color.

Setting the theme. Assign a value from StiViewerTheme and adjust the appearance in the viewer options:
@using Stimulsoft.Report.Web;

@Html.StiNetCoreViewer(new StiNetCoreViewerOptions()
{
    Actions = { GetReport = "GetReport", ViewerEvent = "ViewerEvent" },
    Appearance = { BackgroundColor = System.Drawing.Color.Gainsboro },
    Theme = StiViewerTheme.Office2013VeryDarkGrayPurple
})
Dozens of themes are available (light and dark Office variants and more), and the Appearance block controls colors, scrollbars and other visual details, so the viewer can be matched to the look of your web application.

Hi. Need any help?