Restructure

web/src/components/theme.js

@@ -0,0 +1,19 @@
+import { red } from '@mui/material/colors';
+import { createTheme } from '@mui/material/styles';
+
+// A custom theme for this app
+const theme = createTheme({
+  palette: {
+    primary: {
+      main: '#338574',
+    },
+    secondary: {
+      main: '#6cead0',
+    },
+    error: {
+      main: red.A400,
+    },
+  },
+});
+
+export default theme;