how to use two colors in label for text in c#

Once I had to create a "Gradient" Label... This is the code (works in Winforms)

public partial class GradientLabel : Label {

public LabelEx() {
    InitializeComponent();
}

protected override void OnPaint(PaintEventArgs e) {
    Font font = new Font("Tahoma", 48f, FontStyle.Bold);
    LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, Width, Height + 5), Color.Gold, Color.Black, LinearGradientMode.Vertical);
    e.Graphics.DrawString(Text, font, brush, 0, 0);
}

}

This is not exactly "two color", but may lead you to a solution.

A work-around. Create a bottom "button" with some of the text, then keep overlaying it with buttons containing some of the characters in different colors and transparent backgrounds, overlaying the bottom "button". I use "button" because all of them are dummy button-shaped objects. Only the top level item is an actual 'button', which really amounts to it having an onclick event.

This is practical enough, by the way, in that it is used in certain types of phishing scams - overlaying the real website data with transparent controls that accept the input, send it back to the scammers, and then either report an error (going to the real page for reentry) or even entering the text into the real screen as the invisible layer goes away.

try setting text property to html text like

lbl.Text="<span style="color:Red;">Pro</span><span><span style="color:Green;">ject</span>";
</span>

from back end of ASPX form.

If you are using WPF it is pretty straightforward.
See my solution in Selective Text Coloring in WPF textBox[^]
You can do it with a Label in a comparable manner.

I'd suggest you to use a RichTextBox, it is a standard component and can be used as a label by setting readonly to true and using HideCaret (see here: https://stackoverflow.com/questions/582312/how-to-hide-the-caret-in-a-richtextbox[^] for example)