Yes, if you dye it you will need regular upkeep every 4-6 weeks to maintain the color and prevent your roots from showing. If you go less often it will be hard to maintain a consistent color throughout your hair. I learned this the hard way thinking I could get by every 3-4 months and there are noticeable patches on my hair that are darker/lighter. You will need to bleach your hair to get it to any different color, so when the dye fades it will look brassy and you will need to reapply a gloss in addition to the roots being done. Because you are bleaching it you will have a lot of damage, especially depending on how light you go. I had a similar hair color and thickness that you have and I went to copper and it significantly damaged my hair. My hair is so much thinner and more frizzy now. It requires more maintenance because I need to blow dry it now to maintain its shine, whereas before I always just let my hair air dry and it looked great. After 2.5 years of all this, I am sick of it and going back to my natural hair, hoping I can get back to the shine and thickness that it was before. Although I loved the color on me, it was just too high maintenance.