fix(module): prevent colors option merge

playground/nuxt.config.ts

@@ -1,4 +1,7 @@
 // https://nuxt.com/docs/api/configuration/nuxt-config
 export default defineNuxtConfig({
-  modules: ['../src/module']
+  modules: ['../src/module'],
+  ui: {
+    colors: ['primary']
+  }
 })

src/module.ts

@@ -19,11 +19,13 @@ export default defineNuxtModule<ModuleOptions>({
   },
   defaults: {
     prefix: 'U',
-    colors: ['primary', 'red', 'orange', 'amber', 'yellow', 'lime', 'green', 'emerald', 'teal', 'cyan', 'sky', 'blue', 'indigo', 'violet', 'purple', 'fuchia', 'pink', 'rose']
+    colors: undefined
   },
   async setup (options, nuxt) {
     const { resolve } = createResolver(import.meta.url)
 
+    options.colors = options.colors || ['primary', 'red', 'orange', 'amber', 'yellow', 'lime', 'green', 'emerald', 'teal', 'cyan', 'sky', 'blue', 'indigo', 'violet', 'purple', 'fuchia', 'pink', 'rose']
+
     nuxt.options.alias['#ui'] = resolve('./runtime')
 
     nuxt.options.appConfig.ui = defu(nuxt.options.appConfig.ui || {}, {