fix ek79 tricolor

Author: ladyada

examples/EPDTest/EPDTest.ino

@@ -32,6 +32,9 @@ Adafruit_IL0373 display(212, 104, EPD_DC, EPD_RESET, EPD_CS, SRAM_CS, EPD_BUSY);
 /* Uncomment the following line if you are using 2.7" tricolor or grayscale EPD */
 //Adafruit_IL91874 display(264, 176, EPD_DC, EPD_RESET, EPD_CS, SRAM_CS);
 
+// 2.7" tricolor with Adafruit_EK79686
+//Adafruit_EK79686 display(264, 176, EPD_DC, EPD_RESET, EPD_CS, SRAM_CS);
+
 /* Uncomment the following line if you are using 2.9" EPD */
 //Adafruit_IL0373 display(296, 128, EPD_DC, EPD_RESET, EPD_CS, SRAM_CS, EPD_BUSY);
 //#define FLEXIBLE_290

src/drivers/Adafruit_EK79686.cpp

@@ -125,8 +125,8 @@ void Adafruit_EK79686::busy_wait(void) {
 /**************************************************************************/
 void Adafruit_EK79686::begin(bool reset) {
   Adafruit_EPD::begin(reset);
-  setBlackBuffer(1, true);  // black defaults to inverted
-  setColorBuffer(0, false); // red defaults to not-inverted
+  setBlackBuffer(0, true);  // black defaults to inverted
+  setColorBuffer(1, false); // red defaults to not-inverted
 
   powerDown();
 }