Yes, and it's about as close a match as you'll ever find. Dulux Paper Mint comes in at ΔE 0.2 from Green Oxide — that's well under 1, which means the human eye genuinely can't tell them apart on the wall. It's effectively the same colour, with an LRV of 62 keeping it light and airy. Since it's standard Dulux rather than the Heritage range, you'll pay less per tin and it's easy to get mixed up at any decorating merchant. For a straight cost saving with no compromise on the look, that's the one to grab, mate.
If you fancy a couple of alternatives — say you're already buying other colours from a different brand and want to keep it tidy — Crown Willow Breeze is a solid shout at ΔE 2.1, which is still very close (under 2.5). It's a touch lighter at LRV 65.9, so on a north-facing wall it'll read marginally brighter, but in most rooms you'd struggle to spot the difference. COAT Detox sits further out at ΔE 3.9 — noticeably different if you held swatches side by side, so I'd only point you there if you specifically want COAT's eco credentials and washable finish rather than a true match.
The "but what about the finish?" question matters here. Heritage paints have a particular depth and a slightly chalky, characterful look that the standard Dulux line doesn't quite replicate, even at the same colour value. So if it's the *colour* you're after, Paper Mint is the answer. If it's the Heritage *finish and feel* you loved, you're paying for that quality and there's no real shortcut.
Practical tip: buy a tester of Paper Mint and brush two coats onto a bit of lining paper, then prop it against your existing Green Oxide patch if you've got one. At ΔE 0.2 you'll prove to yourself it's the same colour, and you'll save a few quid every tin from there on.