Colour matching can be tricky. When you start planning a wedding you soon discover that there seems to be at least four shades of white and twelve shades of ivory! What may look burgundy to some, may be described as wine by others. I can remember for my own wedding I asked for gold/champagne roses. I definitely got peachy/orange!
There a a few tips that can help you remove some of the potential pitfalls of colour matching:
Where possible, obtain physical colour swatches that you can compare.
If you can, always compare colours in natural light. Artificial light can be harsh and not your friend!
Share details with all your suppliers - be it a physical colour swatch, a pantone colour reference, a ribbon colour or something that they can make reference to.
If you cannot obtain a physical colour swatch, my top tip is to use dulux paint sample cards. Once you find your colours they are very simple to share as a point of reference and are something inconspicuous that you can keep with you. They are also very useful if you find you need to find colours with the same tone.
Lastly, don't fret. If you cannot match exactly, use colours of a similar tone or make it look like an intentional contrast. Ribbons can be used with great effect to link things such as invitations, bouquets and chair covers, with the ribbon providing the colour consistency.
Ultimately, there is always a work around and don't be afraid to ask your wedding suppliers for suggestions.