景色：only refer to the sightseeing, the whole view you see presented by envoirnment , a certain place, as a picture
风光：it can refer to the concrete sightseeing present by a certain place, (usually a great and wonderful 景色)also, it can and mostly refer to the abstract concept, it is a kind of feeling that you towards sth, And it can be used as a adjective;
a. 这儿的风光真好。 this is similar to the meaning of "这儿的景色真好"， however, the first sentence includes a wider aspects or sometimes only refer to the natrual elements like sunshine, air, color,etc are very amply and rich.
b, 您真风光。 means you are really someone, you have something that could be rich, powerful and so on, which people are very envy you, or respect you.
风光， is a very wide-used word; if you intrest in it, you can try to find out what are the meaning of these words:
I hope this can help you.