Personally I like the blue color. What's so great about black. I have a black Giant Sedona now. Next time I'm definitely getting one with more character. Black is boring IMO.
That said, And you really like the color of the 2020 better, I would look carefully at exactly what has been changed. I like the new head tube and wider tires as well as the color. But if the 2020 checks all the right boxes, It might be good for you too. I much prefer a comfortable ride, so I would look carefully at what has been done to improve it.
The 10% discount wouldn't effect my choice for a bicycle. On a washer or vacuum cleaner OK, But not something I have a passion for.