The semi-permanent is not such a good choice if you have a lot of grey. Also the red tones are the last ones to wash out (if ever) and my hairdresser (I've just begun seeing a hairdresser after decades of doing my on hair) says that the red tones are ageing, look unnatural and are a problem with my hair. HOWEVER - I can use a purple shampoo to tone out the orange.
It's because my hair especially, tends to 'grab' the red tones.
Other things to remember - go for a shade or two lighter than your natural colour, as you get older and greyer.
I found that if I switched around too much between different brands, I risked a 'wrong' shade. One time a shade which should have been lighter (described as medium brown) came out almost black and it made me look awful; I had to buy a dye stripper which turned my hair patchy orange. After that, I stuck to my usual brand.
I would use a permanent colour all the time, but sometimes put a semi-permanent over it to mask the skunk stripe for a while. I also began to treat roots with only half the mix. That meant I kept the nozzle bottle from the previous treatment (after I washed it out thoroughly) and next time, to use only half, I carefully measured out half of each pack (the liquid, then the squeezy tube) and that way I still had half the pack unmixed to keep until next time. Just to do my roots. I found it was more than enough and cut my hair colour costs in half.
Marg