Just to be sure, the suggested Vallejo colours would be:
029 Dark Earth
012 Dark Green
Some people like them, but others also feel they are too dark. So it's difficult to say if this is just a personal preference, or if they are being influenced by others' artwork (models, canvas paintings, digital artwork) or are they comparing to the actual wartime chip?
Both these colours should be dark when factory fresh, but if you consider sun bleaching, weathering, and even scale effect, then of course you can lighten them up. There is also a modelling trend when approaching a camouflage scheme, to lighten just one of the colours but keep the other dark to give more 'pop' to the appearance.
You can try lightening with some yellow and just a little white paint. Or try a light tan. Keep in mind too, if and when you apply a flat coat, this will lighten the appearance of colours.
regards,
Jack