diff --git a/ColorButton.ahk b/ColorButton.ahk
index 46c06b3..d0a94c8 100644
--- a/ColorButton.ahk
+++ b/ColorButton.ahk
@@ -363,7 +363,7 @@ class _BtnColor extends Gui.Button
         this._hoverColor    := _BtnColor.RgbToBgr(BrightenColor(this._clr, this._isDark ? 20 : -20))
         this._pushedColor   := _BtnColor.RgbToBgr(BrightenColor(this._clr, this._isDark ? -10 : 10))
         this._clr           := _BtnColor.RgbToBgr(this._clr)
-        this._btnBkColor    := (colorBehindBtn ?? !IS_WIN11) && _BtnColor.RgbToBgr("0x" (this.Gui.BackColor))
+        this._btnBkColor    := (colorBehindBtn ?? !IS_WIN11) && this.Gui.BackColor && _BtnColor.RgbToBgr("0x" (this.Gui.BackColor))
         this._borderColor   := _BtnColor.RgbToBgr(borderColor)
         
         if !this.HasProp("_textColor") || IsSet(txColor)