chore: add color in hex to fill map

Author: arunjaindev

src/css/iconTheming.scss

@@ -89,6 +89,7 @@ $svg-fill-hex-to-var: (
     "#9FA4A9": --N600,
     "#080A2D": --N800,
     "#C58D36": --Y600,
+    "#FFF5E5": --Y100,
 );
 
 // Using where to have lowest specificity (0,0,0)