ASP.NET MVC - @Import LESS variables returned from controller

[Rod Early]

I am attempting to return LESS variables in the response from an ASP.NET MVC controller method -- which are @imported into the body of a LESS file. The purpose is to allow users to customize the appearance of of a multi-tenant web application. This almost works. public class StyleController : Controller { // GET: Style public string Index() { var ResponseLess = new StringBuilder(); ResponseLess.AppendLine("@color1: red!important;"); ResponseLess.AppendLine("@color2: green!important;"); Response.ContentType = "text/css"; return ResponseLess.ToString(); } ... }; The sample.less file that imports the response of the above controller... @color1: yellow!important; @color2: lime!important; h1 { color: @color1; } h2 { color: @color2; } @import (less) url('http://localhost:50274/Style/Index'); Also in BundleConfig.cs, I include the following to include the LESS files... bundles.Add(new StyleBundle("~/Content/less").Include("~/Content/*.less")); I had to define the variables @color1 and @color2, otherwise I get an error that those variables do not exist. I can see in the Chrome Debugger Network monitor that the StyleController Index method returns the response I expect -- the LESS variables. However, LESS apparently is not recognizing those variables; most likely it doesn't consider the response to be valid LESS. What am I missing or misunderstanding? Thanks, Rod Early

(Also posted on StackOverFlow