Realism

I am a confused realist. I think that there are concreta, material things which exist independent of our minds, and abstracta, ideas which are purely subjective. I think that properties, colour or texture or tone or taste, are subjective to the extent that they are mediated by the emergent 'thing' that is consciousness, and therefore abstracta. But I have some huge conceptual problems. Is consciousness itself abstract? And what about number? Obviously to the realist number is a property of concreta, but it is also a property of abstracta. One can imagine 'three different imaginary items'. It seems to me that number is both a simple property of concreta and a metaproperty of abstracta. But perhaps this is a category error. Perhaps number is a simple property of abstracta. Perhaps number is the only Platonic form. Any elucidation of these ramblings would be much appreciated.