What about if they are very tight, black, and flare out at the bottom? Not those loose trouser suits. I always feel like a super feminist and unsexy in any work pants even tight ones. But when I dress casual I always wear jeans or leggings with no problems.
If you have a nice ass and the pants are well fitted, they can look great. There was a girl in my office who had a sublime ass and wore these dress pants that fit her butt so well you could make out the curves of each individual butt cheek. I remember coming into the copier area and she was there and just seeing her butt in those pants for 2 seconds started giving me an erection.
So no--definitely not ugly. Just make sure you've got the build for it and they fit right.