All purpose thread is the most commonly used type of thread to construct garments and most projects. All purpose thread is offered in a huge selection of colors but that doesn't mean your always going to find the perfect color.
Almost all print fabric has one color that is predominate or the background color. That background color is the color that you want to match when you choose the fabric. Even if the back side of the fabric is white and all of your stitching will be inside the item, you want the thread to match the right side of the fabric.
When an exact color match is not available, choose the closest match with the color being slightly darker rather than lighter.
Choosing a thread color for topstitching does not mean you have to have top stitching in the same color as your construction thread. You can make your top stitching stand out by using one color in the fabric or a contrasting color. It's a choice you make because you are designing your finished item even if you are using a commercial pattern.
Thread does age! Test the quality of the thread by trying to break it and feeling a section of the thread for smoothness. If the thread breaks easily or it feels lumpy, throw it away! It's not worth having unreliable seams that could break open, usually at the most inopportune places and times, rather then spend the money on a new spool of thread.