It's OK to mix under the cicumstance, They'll adhere adequately assuming they're not practically the same. I've used 3M yellow super adhesive at such times, others too.
I will though say that under the best of circumstances, using the exact same is better as it coheres. Glues essentially do work well together. The best reason that I used the same one type(Clement) is that I didn't need to clean the rim so thoroughly every time I changed the tire, the spirits in the new stuff reactivates the old effectively. So if you change the tire in the future, you may want to clean it well the very first/next time and have plenty of the same and you can stick with it.