Not sure it this is the right subforum. It is however graph-related, so here it goes.
I want to export an rgb image of a sentinel 2 product using a graph that yields the same result as doing the following on the GUI: select B2, B3, B4, open an RGB window, then save view as image.
My current graph subsets B2, B3,B4 and saves as png. However, the image looks grayscale and extremely dark. Information is there, though, and can be seen after tweaking levels on an editor.