Selecting which side of a board to place a symbol ("part")

Layout Footprints
21

Just the idea of naming a side “red” and “blue” is quite strange. Why not stick to “top” and “bottom”?
And obviously, everybody will place the meal on the top side of a dish. And only if you run out of space start smearing the sauce to the bottom of the dish. And everybody will realize that this will result in handling problems.

So should the top layer be changed to green to signal “OK” and the bottom layer red to signal that thats where the ketchup belongs to?

Ah, I see! We need a version for vegetarians and meat eaters. A rare steak goes to the top and red, but broccoly for the vegetarian to the top and green. Has anybody ever thought about the right pronouns for bottom, top, red, green, blue, them and theirs layers?

22

Actually KiCad uses Front and Back nearly everywhere, also in the documentation. The only place I’ve found so far using Top and Bottom is the Type description in Board Setup > Physical Stackup.

OP is a newbie so cut them some slack. Colours should be avoided because KiCad has used different colours for F and B in the past.

23

There is some convention to this when double sided boards fist became common, dating back to PCBs in 19" rack card guides, with the assumption that tall THT components were on the front or top side and only the solder and cut leads on the bottom.

Then Japanese consumer equipment like CD players started putting SMD on the underside to use the wave solder process