[Feature][UI Next][V1.0.0-Alpha]Adjust font color in dark mode (#8606)

* Added theme color modification field

* Adjust font color in dark mode

dolphinscheduler-ui-next/src/themes/modules/dark.ts

@@ -18,6 +18,7 @@
 const dark = {
   common: {
     bodyColor: '#141414',
+    baseColor: '#f8f8fc',
 
     /**************** Brand color */
     primaryColor: '#177ddc',