fix: dark mode bug for legend

Author: suhasmatapathi

src/chart/graph/component/button/GraphChartLegendButton.tsx

@@ -134,7 +134,7 @@ export const NeoGraphChartLegendButton = (props: GraphChartVisualizationProps) =
             padding: 0,
             marginTop: '0.2rem',
             fontWeight: 'bold',
-            color: '#535a65',
+            color: isDark ? '#ffffff' : '#535a65',
           }}
         >
           LEGEND

src/component/theme/Themes.tsx

@@ -157,6 +157,24 @@ export const darkTheme = createTheme({
         },
       },
     },
+    MuiPopover: {
+      styleOverrides: {
+        paper: {
+          backgroundColor: '#1e1e1e',
+          color: '#ffffff',
+        },
+      },
+    },
+    MuiListItemText: {
+      styleOverrides: {
+        primary: {
+          color: '#ffffff',
+        },
+        secondary: {
+          color: '#9ca3af',
+        },
+      },
+    },
   } as any,
   breakpoints: {
     values: {