Hi Pete welcome to the board
did you get any original paperwork with the car ( by the way looks mint

) history or owners books should give you the paint code in these , if not there should be a plate on the car that give the code .
Where it would be located on your mx I'm unsure , but my Xedos its in the engine bay, get the code and check it out against these madza codes below
some green codes
Willow Green - 6Y
Teal Green - 18V
Sparkle Green - 11R
Seychells Green - 20Q
Noble Green - VQ
Noble Green II - 11N
Maya Green - 15Q
Marina Green - 13C
Laurel Green/Excellent Green - 11Q
Luna Green - J7
Emerald/Vivid Green - 16P
Fern Green/Lime Green - G6
Fern Grey/Mid Green - 15X
Forest Green/Neat Green - 5S
Gardenia Green - 5U
Grace Green/Racing Green - 18J
British Racing Green - HU
Astoria Green - 22N
or blue codes
Misty Blue - U6
Montego Blue - M8
Neptune Blue - A1D
Pacific Blue/Carribean Blue - 4Y
Regent Blue - DR
Satellite Blue - A5
Solomon Blue - 12L
Solomon Blue II - 11P
State Blue - 15L
Stella Blue - Q2
Twilight Blue/Racing Blue - 12K
Crystal Blue - 23C
Harbour Blue - 5D
Ice Blue - 22L
Indigo Blue (metallic) - 12N
Indigo Mica - 1V
Innocent Blue - 20P
Laguna Blue - 6W
Mariner Blue - DU
Medium Blue - 16S
Canarian Blue - Z2
Carribean Blue - Z1
Conneticut/Ocean Blue - J1
Aster Blue - TD
Bay Blue - DV
Bayside Blue - 1E
Black - 16W
Brave Blue - 5N
Bright Blue - A2E
Aquarius Blue - 12R
Artic Bue - F2
or black codes
Ash Black - 15P
Brilliant Black - PZ
Brilliant Black II - HX
Brilliant Black II - A3F
and this odd one
Malachite - Z8
Regards and welcome
roland