Working an elaborate, multicolored needlepoint design need not be daunting. The main problem most stitchers have when working this type of design is starting and stopping their threads, and the mess the start-stop process leaves behind.
The best way to tackle a complicated multi-color design is to work with multiple strands of yarn at a time, working the colors without starting or ending the threads at the back of the work each time you have a color change. Otherwise, having to constantly end and restart yarn colors creates bulk, and a mess of "fuzzies" on the back of the work. Starting and stopping yarn colors also time-consuming.
This method of stitching applies to both charted designs and painted canvases
To work with multiple colors, thread a length of yarn for each of the colors needed onto a separate needle. Start stitching your design using the first color (color A). When you have finished a section with color A, bring the thread for color A up at the area of the design where color A is needed next - but do not take a stitch yet. Next, work color B, and bring it to the next area where color B is needed, etc. Do this for each color of thread.
The beauty of this technique is that each time you bring the thread to the next area of the piece and work the area in between with the new color, you will work over the length of the previous thread on the back of the work with the new color. This will keep the backside clean and free of bulk and prevents the dreaded fuzzy ends that try to pull themselves to the front of the piece as you work.

