Hand-dyed yarns tend to fade over time. It's a bummer, but it's true. Here's a few tips to help reduce the fading.
1) Don't leave your woolies laying out in the sun. That means don't dry them on a line, leave them on the floor in the sun, store them in a clear container... Don't take this to the extreme. Do let your little one play in them outside.
2) Use unscented wool wash to clean them. The essential oils used to fragrance wool wash encourages the dye to fade and bleed.
3) Don't let your woolies soak in wool wash for extended periods of time. When you wash your woolies let them sit for about 15-20 min. If you let them soak for more than 30 min., the dye will start to bleed into the water.
4) If the dye in the yarn begins to bleed into the water when you wash your woolies, reset the dye.
Hopefully you can learn from my mistakes. Here's one of the first longies that I made when they were brand new:
And here's the same pair after 15 months of love and abuse: