i did a touch up job on one of the rear doors on my car(first timer) and when the touch up paint dried,its color is darker than the original paint :( what can i do?!it was just a 2inch scratch that im trying to repair but now it looks worse :'(oh and one more thing,i oversprayed clear coat and it's not leveled with the rest.heeeeelp!!!

Did you spray or brush? See https://www.paintscratch.com/touch-up-paint-directions/blend.htm for information on blending paint if you sprayed. If you brushed the paint and it is a metallic, is is difficult to get a good match. Also, did you use rubbing compound on the clearcoat?

i used brush :( and i just found out that for bigger scatches,spray is required,so how do i fix this?how can i remove the dark spot?

You can just sand the area and repaint it. I would probably prime it also before painting as this makes for a better finish.