1. The question would be better phrased to cover the other options - environmental factors, developmental factors (in utero & later), epigenetics, culture, & possibly more.
2. We've got the genetics of eye colour sorted out but practically everything else is complex. This, I reckon, is because evolution has worked out that there's a balance between hard coding everything in genes ( so benefiting from inherited characteristics) & being very adaptable (nothing is fixed) but passing nothing on.
So the answer is that it's not 'either /or'.