disguising veg - help please!

[supersnowydaybaby]

This has probably been covered a zillion times over but humour me...
pureeing veg and hiding it in cottage pie etc - i like the idea, but if you puree carrots, they turn it orange, peas turn it green etc etc and the problem is not solved as while the veg is "hidden", multi coloured sauce does not go down well at this fussy house!
does anyone know of a natural brown food colouring (seriously!)as gravy granules etc dont do the trick (plus too salty) and scurvy is bound to set in around here sooner or later!! i am a bit of an anti preservatives crap, up organic type so the healthier the better please but any tips most welcome!
ta muchly....

if you mix pea puree and carrot puree do you not get brown anyway? Problem solved

you can put carrots into tomato sauce... barely changes the colour at all

i wouldn't have thought pureed peas would turn gravy green??? unless you're using a LOT of peas.

i grate it finely or puree it.

Grated parsnips don't show up at all, and are good for thickening soups and stews. Turnip, swede, cauliflower and celeriac don't change the colour of the food either. You can use carrots, butternut squash, peppers and so on in tomato-based sauces and you can barely see them once the dish is cooked. If you peel them, courgettes almost disappear once they're cooked - the flesh just falls apart and you can't see it.