Permanent Color Over Semi Permanent...Can I?

[daffodil7]

Okay. I have relaxed hair with some grays. I was wanting to cover the grays with a non damaging hair coloring option, so I opted for black. My natural color is soft black with some gray.

However, the black semi permanent color (Dark & Lovely Reviving Colors Semi-Permanent Haircolor Radiant Black 391) lasted all of a 2 weeks, before the grays are showing through.

I can tell there is still some semi permanent throughout, but the grays are practically bare. Plus, I want a more vivid blue black I think anyway. Can I just go ahead and put permanent color on my hair? I know I've heard of many women alternating between permanent and non permanent, using semi's every few weeks to boost color and only permanently dying the roots when necessary. So I have heard of some women using both semis and permanents regularly.

So can I do permanent dye of the whole head and then just maintain the roots, maybe use semis to boost shine every so often thereafter?

I also know that going darker is supposedly less damaging to relaxed hair, so I am hoping just going permanent might be an okay idea for me?

My hair is doing well. I don't want to damage it. I will also use coconut oil on it before coloring permanently. I really want to keep my hair growing healthy, but these grays have got to go. Any advice would be helpful. Even if you know of a good semi permanent blue black that will really, truly cover and hold onto grays for a reasonable amount of time that would help.

If I go permanent, I was planning to go with Garnier Nutrisse Ultra Color Permanent Haircolor Ultra Reflective Blue Black ideally because I want a more unnatural, vivid black, or possibly Colorsilk Natural Blue Black if I hear bad things about Garnier and have to settle. I used to use Colorsilk browns to lighten several heads of hair ago, and never had any problems with their products. Now that I am trying to grow healthy hair though, I have been avoiding permanent dyes. I relaxed because my natural hair tends to knot and relaxed hair is just easier for me.