Navy with grey is classic. I am not too worried about security guards ! I have 2 light tan/beige jackets. One lighter than the other. I personally find a bit hard to match them. I do wear those 2 jackets with grey pants. But really light coloured and light weight grey pants. Cream/beige is sort of day time and a bit casual in my opinion thus works better with a bit casual pants. Fabric wise linen and light weight oxford.