Hair color has come a long way. Paul Mitchell professional hair color, for example, has a very low ammonia level in it. But all permanent hair color contains ammonia, no matter what anyone tells you. If that is something you chose to avoid, then you still have options. 

Foiling your hair is a great way to add light or dark colors in a variety of ways. Foiling your hair allows you to add more than one color at once, and you can make a big impact with a few or a lot of foils. When foiling hair you are separating out pieces of your own hair and adding color right where you want it. This color is put on and into a foil; it does not touch your scalp, so it is not going into your system in any way. Hair itself is dead once it grows through the scalp. So while you are pregnant you can at least add some foils to keep your hair looking its best. 

Another option is a semi- or demi-permanent hair color. It deposits on the outside of each hair strand and does not deposit to the inside of the hair. This means that you can only stay the same shade you are or darker - you cannot lighten hair with a semi- or demi-permanent hair color. These shades will blend away gray and add tons of hydration and shine to your hair. They last about four to six weeks and fade off over time without giving you a root line. 

Enjoy every single minute of being pregnant. I know it feels like it is dragging on and you just want to hold your baby. I am the mother of a 13 year old and a 4 year old. I can't believe how quickly it flies by. You need to take care of yourself always, and especially when pregnant. Take time to relax and go see your hairdresser for something to perk you up and make you feel your best during this time.