Instructions from Kodak's website:
"Use with warm-tone papers to produce several cold brown hues
Use to extend print life without changing the image tone on black-and-white paper
Used for archival processing
Dilute 1:20 for print protection
Dilute 1:20 or 1:40 to increase shadow contrast and maximum density with a minimum tone change"
I'd suggest 1:10 dilution for colour change. Don't rely on Kodak's line about protection without tone change - that has been disproved now.