The reason fluid leaves at the arterial end of the capillary bed and returns to the venous end of the capillary bed is the difference in hydrostatic pressure.
If you are looking for the right car paint for your vehicle, then one way to find the match is to look at the VIN number and find out the correct car paint codes from this detail.
There are many websites as to the information available from the Vehicle Identification Number. IF you have done the correct procedure or even looked in the owner's manual of this vehicle you could have located the information as to the VIN number. There is no color code in the VIN number.