mustard coloured poo normal?

[EJ87]

My mare has did some mustard coloured poos today she normallys does ones that are dark brown nearly black but she was in for couple days due to weather and on just soaked hay and bran mashes. is this normal? she was out today and when i brought her in she just picked at her hay but ate her feed drank water and pooed do u think she ok and just a
bit stuffed on grass? she does seem very tierd practically draged her into her stable.

 

[Wagtail]

Yes, if a horse is on grass then the droppings are very dark. After a day or two on just hay then the droppings go a lot lighter and browner, sometimes quite pale.