The state of your poo is actually a really good indicator of your overall health. Care homes and the like actually keep poo charts where the type of poo the patient has is noted down. Colous also important.
So normal poo is light to dark brown. It should be semi solid with a mucus coating.
If your poo is yellow you may have an infection so if it persists talk to your doctor.
Poo can be black or red due to blood in your poo or possible some medicine you took.
Green and grey are also not particularly good.
There is a compound called prussian blue and it is used for heavy metal poisoning and it will turn your poo blue.
Before you panic though, remember that what you eat can have an effect on your poo!
As for texture, there is something called the Bristols Poo scale. It lists 7 types of poo
1) Separate hard lumps
2) Sausage-shaped but lumpy
3) Like a sausage but with cracks
4) Like a soft smooth sausage
5) Soft blobs with clear edges
6) Ragged bits, mushy
7) Watery with no solid pieces. Liquid
1 and 2 mean you may be constipated. 3 and 4 are normal esp 4. 5–7 may mean diarrhea.
If you are constipated or have diarrhea go talk to pharmacist and they can give you something to help and advise you.
Hope that helps a bit!