We do not take the color of a wine for granted: the color evaluation scale is varied and there are more than one.
Some start from the white color that indicates a young wine, drained, sometimes still too young to drink to end with an orange or coppery yellow for a raisin wine or worse spoiled.
The yellow color is given by the type of grape and the steps it undergoes before ending up in the bottle.
It is called white wine by convention and because, perhaps, to say that the wine is yellow would seem to affirm that the wine is sick.
Most of the time, during tasting, the wine is defined as straw yellow in color, for example, with greenish or golden yellow reflections.
These are references that are used to indicate the type of product and its characteristics.
The important thing is that the wine is "healthy" without defects.