Headings in hero mode don't follow the color scheme switch (dark|light)

[simonedimaria]

Describe the bug
Headings in hero mode don't follow the color scheme switch (dark|light)

Hugo & Blowfish versions
Blowfish version: 2.81.0, Hugo version: hugo v0.140.2+extended linux/amd64 BuildDate=unknown

Additional context
The issue relies on the color being hardcoded in the hero.html partial here. The above lines for Author name have also hardcoded color but i think it's fine since it should contrast the user-supplied hero image. While for the heading, the headline being markdownified, if it's e.g. a code block, the text will be sorrounded by a background color that follows the color scheme (dark|light), thus becoming unreadable in light mode since the hardcoded value for the text is currently light in color.