How do I create a color changing hover effect on portfolio item titles/links?

Hi there!

I'm trying to find a CSS code that will change the color of my portfolio item titles/links when the mouse hovers over them. The portfolio layout I'm using in Squarespace is "Hover: Background" (see attached screenshot).

I tried adding the following code to the Custom CSS section of the website's global settings, but it only seem to be working on hyperlinks:

h1, h2, h3, h4, p {

a {

  transition: 0.2s;

  &:hover {

color: #000000 !important;

}

}

}

Is there a crucial step I'm missing, or am I using the wrong code altogether? Thank you!

Thank you so much!