fix(VTextField): prevent TypeError when color is an empty string (#6982)

fixes #6981

Author: KaelWD

packages/vuetify/src/components/VCounter/VCounter.ts

@@ -5,7 +5,7 @@ import '../../stylus/components/_counters.styl'
 import Themeable, { functionalThemeClasses } from '../../mixins/themeable'
 
 // Types
-import { VNode, RenderContext } from 'vue'
+import { VNode } from 'vue'
 import mixins from '../../util/mixins'
 
 /* @vue/component */
@@ -22,11 +22,11 @@ export default mixins(Themeable).extend({
     max: [Number, String]
   },
 
-  render (h, ctx: RenderContext): VNode {
+  render (h, ctx): VNode {
     const { props } = ctx
     const max = parseInt(props.max, 10)
     const value = parseInt(props.value, 10)
-    const content = max ? `${value} / ${max}` : props.value
+    const content = max ? `${value} / ${max}` : String(props.value)
     const isGreater = max && (value > max)
 
     return h('div', {

packages/vuetify/src/components/VLabel/VLabel.ts

@@ -6,7 +6,7 @@ import Colorable from '../../mixins/colorable'
 import Themeable, { functionalThemeClasses } from '../../mixins/themeable'
 
 // Types
-import { VNode, RenderContext } from 'vue'
+import { VNode } from 'vue'
 import mixins from '../../util/mixins'
 
 // Helpers
@@ -21,7 +21,7 @@ export default mixins(Themeable).extend({
   props: {
     absolute: Boolean,
     color: {
-      type: [Boolean, String],
+      type: String,
       default: 'primary'
     },
     disabled: Boolean,
@@ -38,7 +38,7 @@ export default mixins(Themeable).extend({
     value: Boolean
   },
 
-  render (h, ctx: RenderContext): VNode {
+  render (h, ctx): VNode {
     const { children, listeners, props } = ctx
     const data = {
       staticClass: 'v-label',

packages/vuetify/src/components/VRadioGroup/VRadio.js

@@ -104,7 +104,7 @@ export default {
           for: this.id
         },
         props: {
-          color: this.radio.validationState || false,
+          color: this.radio.validationState || '',
           dark: this.dark,
           focused: this.hasState,
           light: this.light