diff --git a/src/boot/after_store.js b/src/boot/after_store.js
index 6c4f0e1b9d..f61e9252eb 100644
--- a/src/boot/after_store.js
+++ b/src/boot/after_store.js
@@ -280,7 +280,7 @@ const afterStoreSetup = async ({ store, i18n }) => {
   const customThemePresent = customThemeSource || customTheme
 
   if (customThemePresent) {
-    if (customThemeSource && customThemeSource.version === CURRENT_VERSION) {
+    if (customThemeSource && customThemeSource.themeEngineVersion === CURRENT_VERSION) {
       applyTheme(customThemeSource)
     } else {
       applyTheme(customTheme)
diff --git a/src/components/style_switcher/style_switcher.js b/src/components/style_switcher/style_switcher.js
index 27df0d105c..76e6cdb79c 100644
--- a/src/components/style_switcher/style_switcher.js
+++ b/src/components/style_switcher/style_switcher.js
@@ -12,7 +12,8 @@ import {
   generateFonts,
   composePreset,
   getThemes,
-  shadows2to3
+  shadows2to3,
+  colors2to3
 } from '../../services/style_setter/style_setter.js'
 import {
   CURRENT_VERSION,
@@ -588,7 +589,9 @@ export default {
       const opacity = input.opacity
       const shadows = input.shadows || {}
       const fonts = input.fonts || {}
-      const colors = input.colors || input
+      const colors = !input.themeEngineVersion
+        ? colors2to3(input.colors)
+        : input.colors || input
 
       if (version === 0) {
         if (input.version) version = input.version
diff --git a/src/services/color_convert/color_convert.js b/src/services/color_convert/color_convert.js
index 6b228a5808..93cb1ba672 100644
--- a/src/services/color_convert/color_convert.js
+++ b/src/services/color_convert/color_convert.js
@@ -185,10 +185,9 @@ export const rgba2css = function (rgba) {
  * @param {Boolean} preserve - try to preserve intended text color's hue/saturation (i.e. no BW)
  */
 export const getTextColor = function (bg, text, preserve) {
-  const bgIsLight = relativeLuminance(bg) > 0.5
-  const textIsLight = relativeLuminance(text) > 0.5
+  const contrast = getContrastRatio(bg, text)
 
-  if ((bgIsLight && textIsLight) || (!bgIsLight && !textIsLight)) {
+  if (contrast < 4.5) {
     const base = typeof text.a !== 'undefined' ? { a: text.a } : {}
     const result = Object.assign(base, invertLightness(text).rgb)
     if (!preserve && getContrastRatio(bg, result) < 4.5) {
diff --git a/src/services/style_setter/style_setter.js b/src/services/style_setter/style_setter.js
index 9610d7996d..b43eb0dd6c 100644
--- a/src/services/style_setter/style_setter.js
+++ b/src/services/style_setter/style_setter.js
@@ -110,7 +110,9 @@ const getCssShadowFilter = (input) => {
 }
 
 export const generateColors = (themeData) => {
-  const sourceColors = themeData.colors || themeData
+  const sourceColors = !themeData.themeEngineVersion
+    ? colors2to3(themeData.colors)
+    : themeData.colors || themeData
 
   const isLightOnDark = convert(sourceColors.bg).hsl.l < convert(sourceColors.text).hsl.l
   const mod = isLightOnDark ? 1 : -1
@@ -283,9 +285,12 @@ export const DEFAULT_SHADOWS = {
   }]
 }
 export const generateShadows = (input, colors, mod) => {
+  const inputShadows = !input.themeEngineVersion
+    ? shadows2to3(input.shadows)
+    : input.shadows || {}
   const shadows = Object.entries({
     ...DEFAULT_SHADOWS,
-    ...(input.shadows || {})
+    ...inputShadows
   }).reduce((shadowsAcc, [slotName, shadowDefs]) => {
     const newShadow = shadowDefs.reduce((shadowAcc, def) => [
       ...shadowAcc,
@@ -374,6 +379,46 @@ export const getThemes = () => {
         }, {})
     })
 }
+export const colors2to3 = (colors) => {
+  return Object.entries(colors).reduce((acc, [slotName, color]) => {
+    const btnStates = ['', 'Pressed', 'Disabled', 'Toggled']
+    const btnPositions = ['', 'Panel', 'TopBar']
+    switch (slotName) {
+      case 'lightBg':
+        return { ...acc, highlight: color }
+      case 'btn':
+        return {
+          ...acc,
+          ...btnStates.reduce((stateAcc, state) => ({ ...stateAcc, ['btn' + state]: color }), {})
+        }
+      case 'btnText':
+        console.log(
+          btnPositions
+            .map(position => btnStates.map(state => state + position))
+            .flat()
+            .reduce(
+              (statePositionAcc, statePosition) =>
+                ({ ...statePositionAcc, ['btn' + statePosition + 'Text']: color })
+              , {}
+            )
+        )
+        return {
+          ...acc,
+          ...btnPositions
+            .map(position => btnStates.map(state => state + position))
+            .flat()
+            .reduce(
+              (statePositionAcc, statePosition) =>
+                ({ ...statePositionAcc, ['btn' + statePosition + 'Text']: color })
+              , {}
+            )
+        }
+      default:
+        console.log('aaa', slotName, color, acc)
+        return { ...acc, [slotName]: color }
+    }
+  }, {})
+}
 
 /**
  * This handles compatibility issues when importing v2 theme's shadows to current format
diff --git a/src/services/theme_data/theme_data.service.js b/src/services/theme_data/theme_data.service.js
index 8c114004be..2cae85de77 100644
--- a/src/services/theme_data/theme_data.service.js
+++ b/src/services/theme_data/theme_data.service.js
@@ -283,12 +283,12 @@ export const SLOT_INHERITANCE = {
     opacity: 'panel'
   },
   panelText: {
-    depends: ['fgText'],
+    depends: ['text'],
     layer: 'panel',
     textColor: true
   },
   panelFaint: {
-    depends: ['fgText'],
+    depends: ['text'],
     layer: 'panel',
     opacity: 'faint',
     textColor: true
@@ -302,7 +302,7 @@ export const SLOT_INHERITANCE = {
   // Top bar
   topBar: '--fg',
   topBarText: {
-    depends: ['fgText'],
+    depends: ['text'],
     layer: 'topBar',
     textColor: true
   },
@@ -313,7 +313,9 @@ export const SLOT_INHERITANCE = {
   },
 
   // Tabs
-  tab: '--btn',
+  tab: {
+    depends: ['btn']
+  },
   tabText: {
     depends: ['btnText'],
     layer: 'btn',
@@ -331,7 +333,7 @@ export const SLOT_INHERITANCE = {
     opacity: 'btn'
   },
   btnText: {
-    depends: ['fgText'],
+    depends: ['text'],
     layer: 'btn',
     textColor: true
   },