What colour to use

Hi looking for advise on the way forward with my hair. I am qualified in hairdressing so understand the basics but haven't did it in over 20 years. I colour my own roots at home but over time felt hair had become to dark. Not wanting to attempt at home went to hairdressers. I only required about 2 levels of lift and hair lifted easily. Hairdresser then put a 6 on. At the time I felt it was slightly to warm for me but was okay. 2 weeks later I had a keratin treatment. This is where it's went wrong. The treatment has lifted pigments and now mid lengths to ends hair a lot of red tones and mid to scalp very orange. Looks okay in darker light but when outside, worried people might think I am an amber traffic light. Question is what to do now. I know i should leave hair a couple of weeks to settle but what colour do I use to counter act the warmth after that. Also I have about 50% grey. That should be appearing on roots soon 🙄 do I put a straight 6 on roots and a 6 with ash on rest of hair? Scared it will go darker. Help please. ☹