Hi Mumto4,
I have to take a cold lunch to work each day too. I follow mainly red days, here are some of the things I take:
Ryvita (or Ryvita Mini's)
Packets of cooked ham
pieces of cooked chicken
Tin of no drain tuna and cucumber
Laughing Cow Extra Light Cheese Triangles
Mini Baby Bell Light
Lots of choppped up free veg/salad
I often take a mixture of these items and cut it up on a plate, and eat like a buffet.
My favourite at the moment is to take a whole cucumber, cut in half lenghtways, cut out the middle and stuff with tuna. This is then like eating a baguette, but with cucumber instead of bread. This keeps/travels really well wrapped in foil.
Hope this helps