What is the conversation mainly about?

W: Hi, Mark, it’s a pretty good painting.
M: Thanks, Judy. I’m just learning.
W: En, there seems to be something wrong with it though.
M: Yeah, it doesn’t look right to me either.
W: I know, the sky doesn’t seem to fit in with other colors of the painting.
M: What do you mean? Everyone knows the sky is blue.
W: Well, that depends. Sometimes it is and sometimes it isn’t, as sunset can be full of reds and purples. Even now, look up now, Mark, what do you see? Do you see a kind of tannish color?
M: Oh yeah, I see what you mean.
W: By adding some tan to your sky, I think you’ll get more actual picture, and the color will look more natural.
M: I’ll try that. How do you get to know so much about painting? Have you taken a lot of courses?
W: No, actually. But my father is an artist.
M: A professional artist?
W: Oh yeah. He’s shown his stuff in lots of exhibits. Ever since when we were kids, he always talked to us about his work.
M: I wish we could talk some more, Judy. How about going for a cup of coffee?
W: I’d love to.