fix constructor for visible black background color

Author: FoamyGuy

adafruit_display_text/label.py

@@ -72,7 +72,7 @@ def __init__(self, font, *, x=0, y=0, text=None, max_glyphs=None, color=0xffffff
 
         self.palette = displayio.Palette(2)
         if background_color or background_color == 0x000000:
-            self.palette[0] = new_color
+            self.palette[0] = background_color
             self.palette.make_opaque(0)
             self._transparent_background = False
         else: