Look for the “Product Stock” widget in the Product widgets. Configure the widget’s settings, appearance, and content according to your preferences.
It has 2 tabs: Content and Advanced.
1. Content
This tab has a Settings and different icon adjust section.
1.1 Settings: Change the in-stock text color. You can also customize the out-of-stock and back-ordered stock text color. Adjust the icon size, gap, alignment, padding, and margin.

Customize the icons for In Stock, Out of Stock, Back Order, and Pre-Order according to your preference.