You need to define your own title resources, you cannot modify the color of the default ones.
For example:
// description.ext
class RscTitles
{
class your_first_title
{
idd=-1;
movingEnable=true;
duration=15;
name="your_first_text";
controls[]={"your_first_text"};
class your_first_text
{
idc = -1;
x = 0;
y = 0;
w = 1;
h = 1;
text = "Your title text";
type = 0;
style = 2+256;
colorBackground[] = {0, 0, 0, 0};
colorText[] = {0, 0, 1, 1};
font = "TahomaB";
sizeEx = 0.1;
};
};
};
In your trigger's EFFECT select type: RESOURCE, and in the list below select your_first_text. Note that after modifying description.ext you will need to reload the mission from the editor for the changes to have effect.