convert float to color

can we able to convert float value of the Color pixel (U,V) to (R,G,B) format(255,120,128) format and display in label the color

Yes, you can display the values in a label.

You can convert a normalized float value to an integer in the range [0, 255] as follows (untested C#):

int result = (int)(value * 255f);

You can then construct a string representing the color as follows:

string text = string.Format("{0}, {1}, {2}", result_r, result_g, result_b);

That isn't the only way to do it, but it will work.