Set FormControl color (#2268)

* Set FormControl color

* Create quick-seas-tickle.md

Author: simurai

.changeset/quick-seas-tickle.md

@@ -0,0 +1,5 @@
+---
+"@primer/css": patch
+---
+
+Set FormControl color

src/forms/FormControl.scss

@@ -48,6 +48,7 @@
 
 // shared among all form control components (input, select, textarea, checkbox, radio)
 @mixin Field {
+  color: var(--color-fg-default);
   background-color: var(--color-canvas-default);
   border: solid var(--primer-borderWidth-thin, 1px) var(--color-border-default);