[SOLVED] Remove white bar between slider on the header right-side-bar and header menu

Hello,

I need to remove the white bar you see here
It's between the header right-side-bar and the header menu.
I tried to follow articles I found here but I could not solve it as I'm not experienced with coding stuff & I'm not sure if my problem is similar.
I'm using "Meta Slider" in that slider adding a widget with that slider in the header right side bar and my theme is "ColorMag"

I would be grateful for any help & if it is alright try to be thorough as I'm new to these stuff.
Thank you.