Perfect colour matching is the difference between trimmings looking okay and looking fantastic.
Colour affects the way we feel about things – but without us necessarily being concious of the effect it is having. You know something looks “right” but don’t always know why it’s right. In this photo the buttons are very, very similar colours and the one to the upper right would probably look okay with the fabric but once you see the one to the bottom left you can see that it just looks much better.
It’s all about combining mixtures of colour. Even if something looks like it is a solid colour I will probably have combined 2 or 3 very close colours to get the over all effect. Colours look less “flat” if they have several close shades mixed together.