For anyone looking for a solution to this- I simply bolded the targeted word in the actual image title. In this example, we wanted to make the text red. Within the code, I also adjusted the font-weight to un-do the bolded part. On the real website, the text will be black but will have a background image, all via CSS.
The CSS code used (Design>Custom CSS) was as follows, targeting the specific block, and then the text:
DevonHarris's post in Code as Image Block Title 7.1 was marked as the answer
