I want the tooltip to display a specific background color for the application while still showing the vulnerabilities and duration normally

I want the chart tooltip to display the application, vulnerabilities, and duration. However, for the application name in the tooltip, I would like it to have a background color.

 this.options.plugins = {
      tooltip: {
        callbacks: {
          // Suppress the default title (duration) rendering
          title: () => {
            return "";
          },
          // Suppress individual label rendering
          label: () => {
            return "";
          },
          // Combine everything in the afterBody
          afterBody: (context: any) => {
            console.log("context", context);
            const apps = context
              .map((item) => item.dataset.label)
              .join(", ");
            const duration = context[0].label;
            const vulns = context[0].raw;
            return [
              `application: ${apps}`,
              `vulnerabilities: ${vulns}`,
              `Duration: ${duration}`,
            ];
          },
        },
      },
    };`

current behaviour for only applications:

Expected behaviour for only applications i want like below colors for: