Color adjustments are easily done by making a new layer from visible (right click on the top layer -> new from visible), then selecting a gradient (with your gradient tool, either go FG to BG and search colors [orange to purple always looks nice

], or take a pre-made gradient like Deep Sea or German Flag Smooth), then go colors -> map -> gradient map on the "New from visible" layer. Finally, change the layer mode to "Color" and turn the opacity way down. This can be done multiple times with as many different gradients as you want.
C4Ds are files created from Cinema4D, a program you don't have to know. Anyway, the files they make look pretty bad*ss and do add a nice touch to most images. Try
this or
this link to find some. Place them wherever you like, resize, erase unwanted parts and play around with the colors and layer modes. But don't overdo it! The subject must still be visible and the main point.
I hope this helped
