I recently dyed my red hair (natural color, but dyed to my "natural" from black), to a brighter red. I wanted a more orange-based red rather than a red-red, so I decided on the Loreal Feria Power Copper C74.
I made sure to take several after pics with and without flash and in different lighting so you can see the color it pulls. I initially wanted to use henna on my hair but haven't fully decided whether I want to or not. This gave me a bright color and I am overall impressed with it, but we will see how long it lasts. I did get a semi-permanent dye from Ion (the Ion Color Brilliance Neon Brights in Blood Orange) to mix with conditioner to use as a "color deposit" for when it starts to fade. My hair has been previously bleached, so it doesn't want to hold onto color all that well, so I figured a semi-permanent for touch-ups might help!
Here are the before and afters of my hair. The "natural" color was a medium auburn that had faded over about 2 months, which is basically my natural grow in color, just for reference. Keep in mind all monitors are different as well. No filters were used on these, just camera flash and without flash.
I hope this helps you out! I will post again on my final thoughts, how I maintain the color and so on! Let me know if you have any questions!