A curlynikki.com reader writes: "...your hair looks like it is jet black, is that all from henna? I'd love to get that dark shiny look."
I know it sounds weird, but the color changes depending on the setting. It's sort of like a rinse...a transparent copper-y rinse. Imagine drawing with an orange crayon on black construction paper—under most indoor lighting, the paper still looks black (albeit shinier), but if held under the light, just right, you'll catch a glimpse of orange. Outdoors, in sunlight, my hair glows auburn, so much so that my sis and hubby call me "redhead", but indoors it's a rich black. There are some instances (back lighting, etc.) where you can really see the red indoors, but I can never really catch it on camera.
With that said, if your hair lighter than mine naturally (sandy brown, etc) the henna red will be very evident—your hair may appear auburn in most lighting conditions.
Many women use a two step indigo treatment to cover stubborn grays and dye the hair a rich, shiny, blue-black. I've never used indigo and don't plan to, but the results I've seen look gorgeous. Hope this helps!
Please leave your henna/indigo mix experiences below!