Make fab text black when primary color is cyan

App.tsx

@@ -26,19 +26,19 @@ export type DrawerParamList = {
 };
 
 export const CombinedDefaultTheme = {
-  ...PaperDefaultTheme,
   ...NavigationDefaultTheme,
+  ...PaperDefaultTheme,
   colors: {
-    ...PaperDefaultTheme.colors,
     ...NavigationDefaultTheme.colors,
+    ...PaperDefaultTheme.colors,
   },
 };
 export const CombinedDarkTheme = {
-  ...PaperDarkTheme,
   ...NavigationDarkTheme,
+  ...PaperDarkTheme,
   colors: {
-    ...PaperDarkTheme.colors,
     ...NavigationDarkTheme.colors,
+    ...PaperDarkTheme.colors,
     primary: '#B3E5fC',
     background: '#0e0e0e',
   },

MassiveFab.tsx

@@ -11,6 +11,7 @@ export default function MassiveFab(
     <FAB
       {...props}
       icon="add"
+      color={color === '#B3E5fC' ? 'black' : undefined}
       style={{
         position: 'absolute',
         right: 10,