Nitpick…black means undetectable colour. There’s heaps of signal level in between zero and undetectable… But since colour is basically what our eyes detect it to be… I guess that will do.
There can be issues with "what our eyes detect it to be " . Bring a moon rock to earth… in regular room light, or outside twilight or night time… it might appear “black”. but we can all see the moon is white…Because the test for colour is done when there is enough light on it to get a reading of colour from the reflection/emissions… Against the night sky, the sun light, at the level of daylight, is reflecting off the rock and being easily detectable a having a white spectrum. But in the reduced light conditions of twighlight or something, the reflection falls below what our eyes can detect… fake black. The crystals in the rock absorb a lot (same as the ocean can look black even on in strong sunlight.)
Back to silver then…
Silver (the element) and other metals (of same look) are often reflective, a mirror. Our brains detect the mirror effect and calls it silver. Our brains detect and correct for shadows and very low angle of incidence reflections, so when we see “silver” on the expected spots on objects, our brains detect that its a reflection (Due to low angle of incidence … Well its not flagged as something unusual , which is to say our brans correctly ignore it… )If we see a mirror, which is a material that relfects even at 90 degree angle of incidence, our brains work out “hey, thats reflective at a high angle of incidence! be careful of that !”