My roots are totally grey and the rest of my hair is henna dyed over chemical color. I first tried the Coppertop color, but it was too orange for my liking. Then I tried the red color and got this. I like the color of the middle/ends of my hair, but the roots are too bright and don't blend in. Can I mix two colors to get a more even tone?

Hi pprinsdeals, This is classic for copper top AKA copper brown. You will need to do a copper/light brown mix to darken it up. This happens when you have white roots.. BUT REMEMBER and this is very important because it will darken over night. So if you just did it, it will get darker over the next 24 hours and the red will tone down a lot, and it looks like you just did it. P.S Nice smile!
Oh and also wanted to add, your hair color is almost spot on with EarthDye light brown. Harvest Moon light brown is more of a chestnut, EarthDye light brown has a hint of red like your hair. I feel you did choose the right color, I am hoping you have just done it and it turns more brown over the next 24 hours. Also make sure you are not using any oils or using any lemons etc in with it... just tap water.
I put the henna in two weeks ago. Used only tap water. It was a lot brighter. It has toned down, but still not enough. So I should mis coppertop and light brown to do the roots?
What about EarthDye Copper Brown Hair Dye?
What if I mixed Harvest Moon Light Brown Hair Dye and Harvest Moon Red Red Hair Dye?
Red red will be fire engine red hair. And I am sorry I missed this, I was out of town a few days. Absolutely the copper brown, here is a picture of a long time customer that uses brown and copper mixed.
To make this easier.... just use the Harvest Moon copper brown, if it is white roots coming in, use EarthDye light brown.
When you have white roots coming in, you either have to do it twice (darker color, then the pure henna over it) or just do a darker color with the red mixed in with it. I am very confident you can match that perfectly :)
The Copper brown turns my white/grey roots to orange. So, if I use the EarthDye light brown, with color red do I mix with it? Or do I mix the copper brown with it? My current color is Harvest Moon red red..