The main problem is typography and your color scheme. Scarlet and teal just do not go together well. And on typography -- there's no full usage of font weights

The main problem is typography and your color scheme. Scarlet and teal just do not go together well. And on typography -- there's no full usage of font weights, so how am I going to tell if something's a heading, or application interface text? I'm no professional designer, but I've had enough experience with applications and design that I know what good design looks like.