Hey and welcome to "Therese mixes colors again"... 😄😅 I often mix different shades of e.g. Maria Nila Colour Refresh or different shades of Revlon's color treatments. The purpose has almost always (except when I tone down Pink Pop with a little brown) been to achieve cool tones without becoming green-haired 😄 Since I am light blonde, I have almost no red/warm pigments in my hair, and there is a risk that a shade that is COLD in ITSELF can make the hair grayish and that the color becomes TOO cold and in the worst case greenish. In other words; I mix in a shade that has red/warm tones with a cool, brown shade (and possibly a little treatment) to balance out the absence of red pigment but only so it doesn't turn green. Makes sense? I've gotten a bit tired of putting in new treatment every other time I wash my hair, so now I wanted to tone it properly. I've read and seen from others that shade 700 is SIGNIFICANTLY cooler than on the packaging, so I have been skeptical about it, but now I also bought Blonde Caramel to hope to balance it. If it's the same brand and product, it should be possible to mix. I took all of 700 and mixed it with half of Caramel Blonde, and you can see the starting state of my hair color in my latest looks on my profile. The result was good! No green, but considering how cool the shade can be, I can only agree that 700 IS very cool. I don't want to know how it would have turned out without Caramel Blonde 😬 Now let's see how it holds and behaves going forward 😁 #loreal #casting #toning