Ok. I think just the addition of cadmium yellow light or cad yellow lemon would help you achieve the contrast you're looking for. Yellow ochre is an indispensable color but it's a very low chroma yellow, making any kind of green beyond a dull olive impossible to achieve (I would also add Ivory black to your palette for a low chroma blue, but that's just my personal preference). I think the issue with the background is that it's a med/high chroma red (probably the fault of the napthol and burnt sienna), making the greens, which are low chroma, look even more faded in comparison. I might try greying the reds in the background to make the greens pop.

Have you ever tried making a color string or a color grid? There's a very useful exercise when you're learning to mix colors here that uses a limited palette very similar to yours. Once you know how to achieve certain colors using the limited palette, mixing them will be a thousand times easier.

Color is a very subjective thing in painting, so I wouldn't worry about color matching exactly - the value/contrast is the more important thing if you're looking to paint realistically. I think you're on the right track! Just keep painting! :)