how to join in another colour of yarn
Do you want to work with different colours of yarn when you are knitting, but you are not sure how? You can buy yarn that has colour changes dyed into it. I am a great fan of self-striping yarn, but it can't be used for every project. Here's a couple of tips to help you join a different colour of yarn to your work.
Note: the two options I've described here are for changing colour of yarn at the start of a row. This works for fair isle knitting and stripes really well. You can use a similar approach when adding a new colour in the middle of a row. This is a technique called intarsia. I have explained in the stitch glossary how to knit intarsia.
A: Sometimes you want to add a new colour to your work, but you want to continue working with the old colour too.
B: Sometimes you want to add a new colour to your work when you've finished working with the old colour.
Picture A: Sometimes you are starting with a new colour, but you also want to keep working with the previous colour (for example, when working narrow horizontal stripes (4 rows or less) or fair isle).
You join the new yarn to the existing yarn by tying the new yarn around the existing yarn with a knot. Slide the knot to the top of the yarn close to your stitches. And start knitting with your new colour.
Picture B: Sometimes you are starting with a new colour, and you have finished with the previous colour (for example, when working wide horizontal stripes).
Cut the previous colour, leaving enough of a tail so you are able to sew the end in afterwards. Knot the new yarn to the old yarn so that the knot is at the top near your stitches and the two cut ends are together. And start knitting with your new colour.