There is no simple way. You really needed to be able to set the color balance to the same thing and with only a JPEG to go on, your ability to do that is drastically limited as color information you need to make adjustments is simply going to be missing.
Say for example that you have a pixel in the image that properly white balanced has a red value that is just shy of the maximum red value. When you have an image that is shifted too far red, now that pixel and any with a much less red component all end up at the maximum.
When you try to adjust the white balance, there is no way to tell the difference between those pixels since the red channel was clipped by the JPEG. You can try to color grade the image to be close (which is still going to be a largely manual process to get right) but fundamentally, chances are high that an exact match is impossible as color information is simply lost.
This is one of the main reasons why shooting RAW is extremely advisable and why, if not shooting raw, it is critical to use a fixed WB when shooting panoramic shots.