How to change font color of partial string in a dialog textbox

Is there a way to change the font color of selected text in a textbox? I can select the required text, but cannot seem to find a way to change just that text (not the entire textbox).

Thanks in advance.

In the text box select the part of the text you would like to colourise. Then (assuming your Toolbar Layout is set to Default) click on Properties (the spanner icon) in the side bar, then click the little down arrow to the right of Font Color (the a with a coloured underline) and pick a colour.

Thanks, and apologies, I should have been more clear.

What I mean is, is there a way to change the font color of part of the contents of a textbox in a Calc dialog, via macro code?