I used DaVinci Resolve 18 to produce the effect.  I started with the red Porsche footage. 

 I used Resolve's Color tab to  sample and isolate the original red color. I used the eyedropper tool to sample different red shades on the car to get all of the red.

Next, I selected the Gain wheel on the Color tab.   I changed the sampled red color to the new blue color.  I used the preview window to make sure all the red had been changed to blue.

I created an alpha output channel for the new blue Porsche on the Color tab. Then I merged the red and blue clips into a new Fusion clip on the timeline.  Next I selected Resolve's Fusion tab.

I created a rectangle mask in Fusion.  Next, I added the lightning FX also in Resolve Fusion. I keyframed the rectangle mask to move across the red car following the lightning FX and reveal the new blue car.

Finally, I used DaVinci's Node layout to connect the clips, mask and FX for the final video. I added an audio effect for the transformation and music for the final video.