matchy up 2.7" to new buffer assignment

Author: ladyada

adafruit_epd/il91874.py

@@ -86,8 +86,8 @@ def __init__(self, width, height, spi, *, cs_pin, dc_pin, sramcs_pin, rst_pin, b
                                                         buf_format=adafruit_framebuf.MHMSB)
         self._framebuf2 = adafruit_framebuf.FrameBuffer(self._buffer2, width, height,
                                                         buf_format=adafruit_framebuf.MHMSB)
-        self.black_invert = True
-        self.red_invert = False
+        self.set_black_buffer(0, True)
+        self.set_color_buffer(1, False)
         self._single_byte_tx = True
 
     def begin(self, reset=True):