Savannah here from the Shopify Guru Team.
The collection titles are changed using the overall heading controls in your theme editor, but if you'd like to specifically change those titles, we can do that through some HTML/CSS reworking. Here's how:
<h1 style= "font-family: verdana; color: pink; text-transform: none;" >
It should all look like this. Of course, you can change the font family and color settings to adjust to your own preferences. The text-transform part just tells the code not to capitalize every letter.
Let me know if you have any further questions!
Savannah | Shopify Guru