Intarsia - Casting on different colors?

Dumb question:

Ok, I’m considering doing an Intarsia project and one thing I don’t quite grasp is how to get the new colors onto the needle.

For example, let’s say I cast on 80 stitches in my main color. I work several rows or round of this color and am now at a point that I want to add another color into the pattern at various points. How do I go about doing this at this point?

I understand that I would have to cut the main color working thread and create bobbins at the places where I need that color, as well as have them in the other color at various points, but I’m just not clear how to get them onto the needle several rows past the original cast on.

Never mind I think I figured it out.

I started a dishcloth using different colors once I cast on my mc and knit 4 rows as a base then when I was ready to use a new color I added it like you would at the beginning of a row but be sure to cross the new with the old so there isn’t a gap. Once you do the next row it becomes a little easier although the bobbins get tangled the farther you go. Amy has a video on this in the advanced section.

Hope this helps