So three green/buff/grey schemes- cool
Be careful to check references as there were two types of buff/green camo - the CZ was finished in either the early hard edged glossy finish or the later feathered edge matt finish. The EZ in hard edged glossy finish. The BZ, R2Z and DZ/D2Z in hard edged glossy camo as well. RZs were delivered in NATO green/grey camo but later painted in soft edge, matt buff/green camo. Also remember that the underside colour for buff/green aircraft was actually a light blue and not light grey.
With respect to tanks (I've put in brackets the Mirage III type where I've seen images of a specific tank combo) :
Two wing mounted RP62 (1,300 liter) subsonic tanks with horizontal fins and endplates - could be natural metal or grey (grey on glow vis RZ aircraft). (Mirage IIICZ/EZ/RZ).
Two wing mounted RP18R (500 liter) supersonic tanks. These tanks had no tail fins. Natural metal, except on aircraft carrying commemorative schemes (Mirage IIICZ #800). (Mirage IIICZ/BZ/DZ/EZ/RZ)
Two wing mounted RP18R (500 liter) supersonic tanks and one centreline RP825 tank (825 liter) - seen pics of RZs in this configuration. The latter tank is longer and larger in diameter than the RP18R and has horizontal tail fins. Both natural metal. (Mirage IIIRZ).
Single centreline RP825 tank (825 liter) (Mirage IIICZ/EZ/RZ)
Two 110G supersonic wing tanks (volume ??) with 3 cruciform tail fins. These are typical of what was seen later on the Cheetahs and Kfirs. Natural metal. (Mirage IIICZ).
Two wing mounted 110G supersonic tanks and one centreline RP825 tank (825 liter). Natural metal. (Mirage IIICZ / RZ).
Also supersonic wing tanks with two bomb shackles in tandem (Mirage IIIC) - not sure of designation. May well be a version of the 110G as they have three tail fins.
Two wing mounted JL100 combined fuel tank (250 liter) / 68mm rocket launcher pods. Natural metal. (Mirage IIICZ/EZ/BZ/DZ).
Two wing mounted RP62 (1,300 liter) tanks and a centreline RP825 (Mirage IIIRZ and R2Z).
Two wing mounted 1,700 liter tanks (Mirage IIIR2Z).
Remember that many of the tanks (RP62, RP18R, RP825 and 110G) were sprayed in an orange protective coating which would flake off making for an interesting finish on a model. Please note that the above is certainly not definitive and is based on actual configurations I've seen in various images found on books and on the net.
note that the Mirage III RZ could also carry the 1700 lt tanks. In this photo 836 also has the tanks fitted.