Before I start, let me say: Color IR is hit-and-miss for me. Sometimes it produces spectacular results, and sumetimes it’s just rubbish! Also, what works here wont work for every image, so experiment!
I’m just going to walk through one example here, so that you get some idea of the process.
This is the original image. It was shot with a converted Minolta S414, with a R72 filter:
First Colour balance. Use the Automatic Color Balance option, with the following settings:
Remove Color Cast (checked)
Colour balance, take 2. Use the Color Balance function, to incease the blues and reduce the reds, You mostly need this across the spectrum, but in this case I used +25 on blues and -25 on reds, only on highlights and midtones.
Have fun! 🙂