Good news. Potentially, unless one wants to use the washing out as a good excuse to skip the fashion colors.It's the cost that would be the issue for me. I let DD (who is naturally blonde) get her ends dyed blue when she finished middle school. It was just under $100 to have it done, and it looked great, for the 4 *days* that it lasted. Our tap water has rather a lot of chlorine in it, and the dye did not stand up to it at all. (It was permanent dye, but had not been lifted.) She was heartbroken when it was gone within a week, but I drew the line at repeating that spend, not to mention the 2 hours that it took to process.
There are now fashion colors that use developer and will not wash out from unlifted hair. They won't show up if it's not light enough but will show up in blonde hair, even cover grey hair. Last as long as any dye that you mix with developer. 4-6 weeks. Some fading but not significant. I've been using one for about 4 years now.