Is it ok to mix two different colors of Loreal hair color?

There are a lot of variables on this answer. If you are using the same brand and the same product line of that same brand (e.g., Loreal Superior Preference vs. Loreal Excellence Creme), then yes, sometimes.

You must first consider the type of shades you are using. For example, it is not a good idea to mix a warm color with a cool color nor is it a good idea to mix opposite colors. The colors must be complimentary, such as a warm brown and a warm red.

It is definitely not recommended to use different brands and not only that, but different hair color lines as well. This is due to the difference in chemical compounds for each product line. They are made completely different and you risk coming up with a strange shade or worse, severely damaging your hair.

One more thing that you may wish to consider when blending hair colors together: be careful to measure your color mix exactly because if you fail to do so, when it comes time to recolor, you'll have a color line that is not well blended.

Old answer: I've been told by everyone not to mix hair colors...but I always do! In fact I mix hair color from different brands to achieve the color I like.