I belive they are called termites
A white office chair is not common but you should be able to find ones of any material from cloth to leather to plastic. This site has a lot of white office chairs: http://www.officechairsoutlet.com/White-Office-Chairs-s/216.htm
If it's spreading, it sounds like there may be a toxin- you should have it checked. Generally with insect bites, 2 "pokes" means spider.
A black Pegasus, for one, though it only bites in defense or when it's eating, and mostly they're white.
Termite
serious bites
Brown rice is a light brown colour and is usually eaten with Chinese dishes where as white rice is white and eaten with more common dishes such as fish.
Amazon has white leather chairs listed as low as $185, as well as more expensive models. Office and desk chairs are quite a bit cheaper than leather chairs for home furnishing.
A termite
termite
Yes - you have observed that the animal is an insect, and those are its colours.
I believe that grey and white reflect radio waves and black absorbs it. That is why large radio telescopes have either white or gray dishes.
Spider bites cause dark brown bruises with a white looking spot in the middle. If you notice any marking like this, contact your doctor for instruction on what symptoms to look for and if you need to be seen.