And even then it will depend on the lighting prevailing at the time and the pigments the swatch is made of. Different pigments give different colours under different lighting conditions. Two colours can look identical under daylight, but look markedly different under artificial light, for example, and daylight changes from morning, to mid day, to evening, and again according to the cloud cover.
The colours you see also depend on how analytical your colour perception is. As everything in life, some people see colours more accurately than others. They will see nuanced variation where others will see “the same colour”. Hell, in my case if I look at something with both eyes, my right eye, or my left eye, I see different colours. My right eye has a definite red cast that warms up colours that I see. It is also the dominant eye in my binary vision.
Of course, you don’t actually “see” colours, what you “see” is energy waves (or is it particles LOL) that are converted to electrical impulses by structures in your eye which are then in turn interpreted by your brain. This means your mood and upbringing can even effect the colours you see. To give two examples. Ancient Greeks couldn’t “see” the colour blue and determined colours by lightness and darkness rather than in terms of hue, hence the “wine dark sea” description. Himba people of northern namibia are able to easily determine different hues and shades of green compared to western peoples.
What this interminable rambling means in truth is that absolute colour fidelity is a myth. In terms of colour matching near enough really is good enough. Exact matching is influenced by so many factors it is impossible without sophisticated mechanical assistance, and even then external influences would bring some to argue that the results were wrong.
The only way you could exactly match an original colour is to use exactly the same paint, made at exactly the same time, and paint the item at exactly the same time that the original was painted. Even then, different storage and atmospheric conditions will create colour drift over time so the two will gradually become different colours. This is obviously impossible, so go with what seems right to you and tell any naysayer to boil his or her head……..