Congratulations - fingers crossed for you - understand the anxiety part in these early stages but its a bit of the case of what will be will be...3 positive tests and the 'classic' symptoms mean all is well so focus on that! Remember reading that you shouldn't dye your hair, or paint your nails...not sure - imagine its the chemicals they want us to steer clear of - have you tried googling the product or is there any info on the label? Otherwise maybe ask your Dr...Keep well.
I think the colour should be ok - no peroxide or amonia - but to be safe, I won't do anything until I speak with my doctor - Google gave me some conflicting information! Everything's fine today, still no real nausea, but a funny yucky feeling when I first wake up, but I'll take that to mean I'm just lucky so far!