If she's your 'precious pet' are you really willing to chance serious injury or death by letting her whelp? Shi Tzu's are known for problematic birthing. Their hips are narrow for the puppies wide heads. Blockage and emergency cesaereans are a fairly common occurance.
If you lack experience and you are not a serious breeder, please reconsider your desire for your bitch to have pups. Color is the least important factor.... The health of your bitch + the stud's family history and HIS size in relation to hers are a critical issue in this matter.
I would suggest discussing this with her original breeder, but since she was bred with no regard to pedigree, I'd doubt that source concerning veracity. Please contact your nearest Breed club for further advice. You can usually locate one via an internet search engine
regards,
toodles