I just did mine in Dubai with the EK doctors during assessment. They have a machine right there. Free of charge.
The test is very hard, the doctor himself said although he can read the entire Ishihara chart he cannot get some of the dots.
I personally missed a lot, so I thought I must have failed. It's a long extensive test which determines in detail your exact colour deficiency. In the end I was mid-scale deficient and had passed.
Good luck