What is "Business Appropriate"?

I have a job now, and I like it very much . in the interview I asked my boss what I should be wearing to work and she just told me "black and white".so the first day I put on my most comfortable sneakers and a really cute sweater which was kind of fancy for a sweater .it was striped and really warm and comfortable,because I thought I have to be comfortable if I'm going to be standing and walking a straight 4 hours. I went in and my boss asked me if I had brought any other clothes to wear.I was shocked cause I usually think I'm ok in the dressing department. she said I told you to wear "business appropriate" clothes. I got a bit confused cause I didn't know what that meant so I asked her and she said oh nothing like maybe a blazer? and you can't wear sneakers,you have to wear either dress shoes or proper dress boots. so the first thing I did when I came back from work was to google "What is business approprate clothing?" the results came up and the main thing that was common in all sites was that I have to wear neutral colors.the second thing was that they said I have to dress conservativley. what does that mean exactly? I figured it meant not showing too much cleavage and nothing too crazy. so I went out to buy some clothes and this is the result. I wore these for my second day at work. and my boss was pleased. but I wasn't. my heels were killing me the whole time.
so I noted to myself "heels,bad Idea." they took away my focus and made me really really tired.
at the end of the day feet are really important keep them comfy. I have to buy new shoes now. although I think the heels really do look pretty.