OK, here ya go.
SIG Arms has announced a new finish for the outside of the models P245 and P220 and for use on internal parts on all SIG's called Ilaflon (TM). Ilaflon is a silicone-resin based coating that is electronically applied as an anti-corrosive coating with very high water and oil [petroleum distillates] resistance. It is applied at 200 degrees C (about 400 F) where it bonds to the metal forming a permanent barrier to corrosion and wear. It comes in several colors as well. It will be applied to the P245 and the P220 and to certain internal parts of all SIG handguns and is an optional finish on other models as specified in the 2000 SIG catalog.
Nitronª is a standard finish for SIG's sig pro¨, P226, P229 and P239 model handguns. Developed exclusively for use on SIG Arms' pistols, the Nitronª finish actually impregnates the stainless steel slide - resulting in a hardened black finish, impervious to rust, corrosion, and the demands of everyday use.
An optional nickel finish is available for many of SIG's handgun models; P220, P245, P225, P226, and P229. It combines an attractive matte nickel slide that accents the standard blued finish for a distinctive, contrasting two-tone look that retains a superior level of resistance to corrosion, rust and wear.
A blued finish is the standard finish for all SIG's other handgun models. The matte blued finish is used on slide, trigger, hammer and levers while alloy frames are hard anodized. The standard blued finish has proven to be exceptionally durable, rust and corrosion resistant.
Bottom line, get anything but blued and you will be happy.