I don't know how to change the outline of my illustrations into different colors. I draw by hand and then I scan the image and place it on Adobe Illustrator. I do the whole process of 'image trace,' 'expand,' 'live paint,' etc., and then I'm able to color it in. But I have been trying to change colors on the outline of my illustrations. For instance, if I'm drawing a person, I want to be able to have a different color outline for hair, skin color, clothing, etc. Some people have suggested using scissors or knife tool. I just haven't been able to do it, though. I'm no graphic designer, I just like to illustrate.
Ma'am / Sir Try this if it can help to your project. Im Using Illustrator CS6.
I have tried also "Rotoscope" before in illustrator. Its time consuming but visually rewarding when finished. In case you want to vectorize an object or a face for example. Knowing the differrence of fill and stroke will be helpful to you. It helps in choosing colors you want. Take time to see the embedded samples.
Note: You must identify first and for most your type of media where you want to display this [whether it is (RGB-TV,Monitor Screen, Wallpaper, Web Page) or (CYMK-Print media e.g. Newspaper, Magazine, labels etc)]. There will be difference in colors.
Here is an image for example in CYMK / Print Media
tracing highlights of hair and give color to them according to your choice.
In Upper Right corner of the screen there is the Fill and Stroke button together. The path that i draw for the hair (color blue on the screen) currently has No Fill and No Stroke as it shows red slash in the middle.
Now try to change the fill according to your chose just blend the CYMK or RGB values. You can also use swatches that you can save to save time.For this example I just roughly estimate the yellownes shading of the hair. See the Fill button is selected and changed in appearance. When you select the path it automatically display the color values in it.
Stroke is also very useful in rotoscoping. copyinng hairline together with other tools like pen or brush tool. You can adjust the thickness and appearance of just mix and match. Designers/Artist Perspective :-)