When you paint your engine,

do you paint everything (with the exception of aluminum parts like heads, intake) the same color or do you ever paint bolt on parts like the oil pan, timing cover, oil pump a different color? I'm getting ready to paint and was going to paint everything the same color but I started thinking it might look better to have a little contrast by painting some of these parts a different color or perhaps just a different shade of the color that I am painting the block.

I prefer to paint everything the same including heads and intake, but them my favorite are modified engines that could pass for stock or basically stock appearing to the uneducated casual observer. Unpainted aluminum quickly gets dull and the grease soaks into the casting pores so IMO aluminum should at least be painted cast aluminum color. But if you're going for more of a race look and you're not trying to pass for stock, then by all means shake it up a bit!

everything the same color with the possible (maybe maybe not) exception of the valve covers being a different (appropriate) color.

According to what look you want. If you want a stock look, then paint everything like the factory did, but if a modified look is your thing the don't paint the aftermarket parts. I have a full aluminum engine, but I wanted it to look stock, so I painted everything.

engine blue,

intake blue if iron, if al. I leave it nonpainted

water pump and such blue

all brackets black

valve covers stock = blue, if cast al. leave alone

if a year of car/engine is suppose to be orange, I paint it blue. orange isn't in my vocabulary.

I'm not going for a stock look. I am painting the block a dark cast iron color. I was thinking maybe it would look good to paint the oil pan, timing cover and oil pump in cast aluminum but then again, maybe not.

Your the builder, it is your deal so do what makes YOU happy
I've painted them without all the lower end fasteners(oil pan, timing cover) and painted them silver for contrast per a customers request It was noticeable

Do you think it looked bad?

this may be a stretch but after seeing some of the offbeat color schemes on car bodies I was thinking of getting a 1/24? plastic model kit car & painting it various combos to see what scheme/color grabs me & I suppose a person could do that with a model engine also (I'd want a bigger model eng). As you know when the time comes triple clean all surfaces & I do a final cleaning by drowning the surface with brake kleen, gets onto the rough surface pores on blocks/intakes etc.

I did that with a picture of my AMX. Got the little touch up paint vials and painted the picture and finaly got the colors I wanted. Had to get the angles correct as well as the shade of the colors.

I usually paint the long block a single color.
Then use black for covers and brackets.
I have used stainless hardware for pans and covers for a little sparkle.
I try to keep it kind of plain looking & stay away from the chrome dress up stuff.

I thought it would be cool once to paint everything separate and use non stock bolts on the oil pan and valve covers. The oil pan got button headed allen bolts. IT looked cool but later with the engine in the car, access to the forward oil pan bolts was a pisser. I went back to standard 6 point bolts after that.

No.
He liked it a lot, it was different. Not bad looking and not impressive by my standards
I'm a racer, not a show car guy so keep that in mind
Performance is much more important to me than looks, just like my women

This. And I get what your thinking about. A little contrast can be cool IMO. My current stuff is painted similar to factory, just like most folks do......kinda boring.

Only one color to paint a 440 and that's orange in my book. Here's my motor as of now.