Hi
@Bonnie23, sorry for the slow reply. Trying to hit an exact colour is always going to be a challenge for a home dyer - if you're happy with the near-enough-is-good-enough approach then I'd be using something like a royal blue, if you want quite a strong, bright, pure purple. If you want something deeper and more subdued, a bit of navy would perhaps give a better result.
If you go with the purple dye, it might be a bit on the fuschia or reddish-purple side, but it may also turn out perfect - such unpredictability!!
Weighing the garment as
@Lachica suggested and then using an appropriate amount of dye for the depth of shade you're looking for is a good idea. Here's my rules of thumb:
Pale shades might only need 0.5 - 1% per weight of fabric
For mid-strength colours, you need about 4-5% per weight of fabric
For the deepest, strongest colours, you will usually need about 8% per weight of fabric (and as high as 10% for black)
No point adding more dye than that, you will just be wasting the dye as there won't be enough sites on the fibre to hold the dye...
If you don't have scales, one level 5ml teaspoon is (very roughly) 4 grams in my experience. So if you were doing a mid shade on 100 grams of fabric, 1 teaspoon of dye would be pretty close.
If the fabric is already bright pink, it might already have 6% dye, so you only have about 2% to get it to that maximum. If it was me, I'd be having a go with about 2% navy and see where I was. But please bear in mind that a) I like dull colours, b) I'm happy to take a gamble that I might over-shoot and make it too dark and c) I am always happy to over-dye it again.
I'd love to see before and after shots of whatever you decide to go with.
And hello
@Francesca, sorry to hear about your splotches. You mentioned that the splotches looked like speckles - this suggests undissolved dyestuff to me. I don't do any washing machine dyeing so my methods might not be terribly useful, but I always pre-dissolve any dye with a bit of warm water before I add it to the dyebath, if I'm going for an even dye effect. You start with a tiny bit of water and make a smooth paste, a bit like making a roux in cooking, then gradually add more water until you have a clear solution, with no sediment or other signs of undissolved dye. That should eliminate the tiny speck problem.
If the splotches are larger, they could be caused by something left in the fabric - like starch or spinning oil, or any number of chemicals that are applied to fabrics and garments. They can often 'pull' the dye towards them and cause sections to dye darker.
To minimise these, your best bet is to give the fabric or garment a really good hot wash, with plenty of detergent - if you don't have a special pre-dyeing detergent, then a good dish-washing liquid is probably your best bet - it's mostly detergent, without too many softeners or other bits that might cause problems of their own. Plenty of rinsing after the wash, to make sure you have a nice clean 'surface' to work with.
@SewRuthieSews suggestion to watch out for fluff is also a good one - it can cause redepositing issues. If the fabric is prone to pilling or shedding, it could be causing its own fluff deposits.
Other suggestions for even dyeing include getting as much water into the machine as you can - water efficient front loaders are probably not the go!
Sorry, I don't have any ideas about how to fix it now - I'd be interested to hear how you go if you decide to strip in off and overdye again.
Don't let it discourage you. Pale, even shades are hard, even for professional dyehouses! We had to work hard to ensure the tiny amount of dyestuff had time to spread out evenly over the entire fabric, before adding the salt and other fixing agents that would hold it in place.
Dyeing can be fun, provided you can see the 'variances' from what you were expecting, as 'opportunities' and don't let them beat you up too much.
Happy dyeing (with an e) everyone! Oh, good gracious, I've just realised how long this post is. So sorry. Hopefully it's helpful along the way.