Soft tan colored stool

Hi, my cat caught a cold few days back and she was sneezing and coughing without vomiting or stool problems. I took her to the vet and she had a couple of shot over two days, today after the final shot she had problems moving her feet and wasn't able to reach the litter box so she did it on the floor next to the litter box. It was a soft tan colored stool. Is this normal? I'm just asking though I will take her back to the vet tomorrow.

Did the stool have form or was it more like a shapeless blob?  Cats that are sick will often have stools that are loose.  You could try a little bit of canned pumpkin in her food and see if that won't help tighten up her stools.  

What exactly happened is I came home after getting her final injection and opened her carrier for her to come put but she was clearly in pain and couldn't move her back feet. I left the room to change my clothes and came back to check on her, there I saw a line of shapeless blobs scattered a few feet from the litter box leading to the box itself, when I checked inside the box I saw two small pieces of the same stool. Seems like she could lift her legs to get I to the box and couldn't hold it anymore. I feel very bad for her because I took her to treat one thing and came back with another problem.

Diarrhea in cats that are ill is normal.  The troubling part is that you say she had trouble moving her back legs.  I would definitely call the vet and tell them that right away.  

I'm assuming she's hurt because of the injection she had today but could a cold shot have caused any side effects like allergic reaction?

I'm worried because we do not have 24 hour vet clinics, all vets here open at 8 am and close by the afternoon. They're all closed by now.

The diarrhea could be a reaction to the shot.  Keep her hydrated and fed through the night and get her to the vet in the morning.  You might want to add additional litter pans by using cake pans that can either be sanitized or disposed of.

Fortunately they said it's a reaction from the injection. She's all good now, thank you.