Yellowing plastic is the bane of all collectors. Despite our best efforts to keep figures from sunlight, smoke, and other environmental factors, many white plastics will inevitably turn that sickly shade. I've previously addressed this problem on my Vintage Collection R2-D2 and Legacy Collection Sandtrooper by incorporating the yellowed plastic into a wider 'weathering' of the entire figure. Unfortunately, I'm not able to do the same with the abdomen of my Legacy Collection BD32 Spacetrooper - so I had to come up with a different strategy.
Before (left) and after (right).
While bleaching is always an option, it's not something I'm yet brave enough to do with my figures. So I opted for something a little less extreme - covering the affected areas with several thin coats of Model Masters Gloss White. Fortunately, the gloss matches well with the rest of the figure's armour and completely removes the unsightly yellowing below!