That’s definitely not possible using software only. You cannot simply “improve” the light source of your phone/tablet/laptop without making hardware modifications. In other words, buy a proper light source suited for this purpose if you care about your color reproduction.
And,
Like I said, you will probably always want to do some processing afterwards. Buying an expensive Epson scanner does not guarantee that you get a digital file that you’re happy with. There’s a lot of factors to consider. How old are your negatives? Are they high quality negatives? Do you need 6.000 ppi scan resolution? Just to name a few. Please read this thread too for some thoughts.
Personally, I have had great experience with my D750 camera with a macro lens, a good copy stand like this, and an Artograph LightPad. I digitised my family’s collection of around 500 positive slides quickly and quite efficiently. An example you can find here.