PROBLEM WITH OLED AND TWO BUTTONS

post your code after you commented out the other bits.

Did you fix your mistake that button 2 has to be both high and low ?
and did you fix the missing end bracket in loop ?

try this :
use your above code
remove loop()
replace it with below code
it should just blink back and forth between colors.

then add one button at a time.

void loop {
    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(20,31);
    display.print("WHITE LEDs SET");
    display.display();
    digitalWrite(WHITE,HIGH);
delay(2000);
    digitalWrite (BLUE, LOW);
    digitalWrite (WHITE,LOW);
    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(0,15);
    display.print("PRESS 1 SET BLUE");
    display.setCursor(0,35);
    display.print("PRESS 2 SET WHITE");
    display.setCursor(0,40);
    display.print("PRESS 3 SET RED");
    display.display();
 delay(2000);
} // end of loop