Properties of color
Shade
A darker version of a color, generally equal to "adding black".

How it affects UI design
Shades are utilized in creating color scales. They provide higher or lower contrast colors for various UI applications like text, borders, or backgrounds.
Related topics
Sources:
- Linda Holtzschue (2017). Understanding color: an introduction for designers. 5th edition. John Wiley & Sons, Inc. Pages 86-87
- Mary Stewart (2006). Launching the imagination: a comprehensive guide to basic design. 2nd edition. McGraw-Hill. Pages 384