DSF

I've used the same colour red on a water bottle as I usually use on my mugs but it has come out different (slightly pinker). Is this difference normal between different sublimation products or could it be time/pressure?

It’s all down to time and material.

mugs are ceramic whereas your water bottles are probably aluminium?
Each need certain time and heat settings to get the right press result.

Of course if it’s cheap products your using that could also affect the outcome slightly.