That isn't JSON: It's just a bunch of strings delimited by double quote pairs concatenated together.
JSON data is hierarchical, and looks like this sample array:
[
{
color: "red",
value: "#f00"
},
{
color: "green",
value: "#0f0"
},
{
color: "blue",
value: "#00f"
},
{
color: "cyan",
value: "#0ff"
},
{
color: "magenta",
value: "#f0f"
},
{
color: "yellow",
value: "#ff0"
},
{
color: "black",
value: "#000"
}
]
I'd start by checking exactly what you are expected to produce, and if it is JSON then use something like Newtonsoft.Json to generate it.