Adafruit SSD1351 fills slowly

I am using the adafruit SSD1351 with adafruits provided library I have found that when I use fillscreen it is quite slow and I can see the pixels filling up on the screen which is annoying as I would like the screen to fill quick enough for a fading background colour change.

I tried using the Freetronics OLED Library and that filled the screen quick enough.

So I was wondering if there was any way to incorporate the way that freetronics fills the screen into the adafruit library, I had a go but could not really get anywhere.