Most other major manufacturers - Massey, Fendt, New Holland, along with Scania, Volvo, and Mercedes in the truck business are using Adblue for emissions control, so John Deere are the exception to the rule regarding the use of EGR/DPF in heavy equipment.
EGR, (exhaust gas recirculation) ie. recirculating soot back into the air flow into the engine, bypassing the air filters is a bad plan.
Combining that with DPF (soot filter on the exhaust outlet) which clogs up as a matter of course, then needs to burn extra fuel to clean itself (regeneration) and eventually wears out and needs to be replaced, madness in my opinion.
Adblue engines run hotter internally, burning up all the fuel in the cylinder (better economy/no soot) with the side effect of producing NOx (nitrous oxide which causes acid rain) which is neutralised by Adblue. This is an extra cost, but the better fuel economy (due to burning the fuel as opposed to turning it into soot) makes up for it, combined with the lack of a DPF to burn out.
Leaving aside your choice of colour, DPF is a bad solution.