Here's why:

* Felsic rocks are rich in feldspar and silica (SiO2).

* Feldspar minerals are typically light in color.

* Silica is also a light-colored mineral.

* The high silica content contributes to the light color and often makes these rocks more viscous (thick) than their darker counterparts.

Examples of felsic igneous rocks:

* Granite

* Rhyolite

* Obsidian (volcanic glass)

* Pumice

Let me know if you have any other questions!