If you can locate a handle to the title "text" graphics object, then you can set the Color property of it. However, this would set the color of all of the text, not just part of it. The title "text" object has a hidden handle:
ax = gca;
potential_title_objects = findall(ax, 'type', 'text', 'handlevisibility', 'off');
If you wanted to set the color of just part of the text of a title(), then you have to modify the String property of the text object, as I described in your previous https://www.mathworks.com/matlabcentral/answers/366350-how-to-change-the-color-of-the-axes-graph-numbers#answer_290461
There is no way to change a property of something without modifying its properties.
