Pourable white rubber/silicone - raised white lettering for tires

Looking for any help/advice. I have a Delorean which i have converted into a Time Machine and am trying to make raised white lettering for the tires. I can still buy the rear size but the front tires are unavailable with white lettering.

I have taken a mold of the raised letters and have poured a set in black flexible rubber. Unfortunately cant seem to find a white 2 part rubber?

Any advice?

regards

Brad

you could try using smooth-on Econ80. it's a one to one compound which comes semi-translucent that you can then dye and opaque to whatever you want. the cost is also relatively low as apposed to other urethane rubber compounds. it's about 25 bucks for trial size that gives you 1.9lbs NET of product which should be more than enough for what you need. check it out HERE

or you could cast in you black rubber,and paint the lettering with white acrylic afterwords. it stays fairly flexible and should adhere to the rubber depending on it's porousness

paint the letters white