Why not edit your video on a simple video editor like Filmora, Cyberlink Powerdirector or other stuffs and do the color grading with the color grading tool talaga just like
NewBlueFX Color Fixer Pro and Colorfast
or
Red Giant Magic Bullet Suite
pero base on my experience lang ay doing color grading needs a GPU because it might lag your PC and forces to close the software for sure since you just have a 3gb ram.
But if you want an editor/best color grader na rin, Davinci Resolve yung irerecommend ko. National Geographic Network uses this Software.
Pero base sa Specs na meron ka, I really don't think na magagawa mong successful ang color grading.
Pero I think doing the editing and Color Grading separately will work but I'm not hundred% sure. You can try tho.
(I feel bad, na konti lang ang Video Production incline dito sa PHCORNER

)