style: onboarding screens (#1539)

* fix: onboarding screen styling

* chore: minor styling fixes

* chore: disable buttons if form is invalid

apps/app/components/core/theme/custom-theme-selector.tsx

@@ -21,11 +21,11 @@ type Props = {
 };
 
 const defaultValues: ICustomTheme = {
-  background: "#292d3e",
-  text: "#ffffff",
-  primary: "#7d57c1",
-  sidebarBackground: "#292d3e",
-  sidebarText: "#ffffff",
+  background: "#0d101b",
+  text: "#c5c5c5",
+  primary: "#3f76ff",
+  sidebarBackground: "#0d101b",
+  sidebarText: "#c5c5c5",
   darkPalette: false,
   palette: "",
 };