Hi everyone, I'm new on this and starting my first paint. I'm having a very hard time on mixing the dar colour of the background. I started with burnt umber and blue... then some read... it was too brown and from then on everything was quite brown. Just lighter or darker but always brown. I'm using some oils I had at home, not artist quality. Actually I tried to mix also only blue and red and it's not a good violet. I'm not sure if the problem is on the mixing or on the colours. Any tip?