Is it ok to have yellowish teeth? i can see that the rims of my teeth are slightly transparent.

The yellowness : One sees is the yellow (dentin) being reflected out from the tooth due to the density (porosity) of the outer layer of enamel. The appearance of teeth in the incisal areas are generally more translucent in appearance. Best to be examined by a dentist if you're concerned and discuss whitening options if interested. Hope this helps.

IF: If this is something new & recently noticed: you may have abraded / worn the enamel (white layer) of the tooth to the point where you see more of the dark yellow (dentin) from within. If the biting edge now appears transparent, you may have worn the inside of the biting edge, making it thinner and somewhat transparent. See your dentist.