Color matching mixing process

There are many available methods for mixing colorants into plastic materials. Choosing a laboratory method that will most closely match the production process is ideal, but not usually the norm. Colorant dispersions in plastic materials determine the perceived color. Thus, choosing a consistent, reliable mixing method that closely mimics production dispersions is critical to a good visual color match. 

After the plaster has been removed, a new plaster as free of iron components as possible will be applied. Either a lime-based mortar or a so-called restoration plaster may be used. After the plaster has hardened, the entire interior must be color-matched to the remaining parts of the church. This is always problematic, since all paints - even lime-based paint - undergo a certain aging process, and mixing the paint to match the ground color present will likely prove difficult. 

When egg whites cook, a small amount of hydrogen sulfide (H2S) is released from sulfur-containing amino acids like cystine or methionine. If the H2S migrates to the yolk, it combines with iron atoms to produce ferrous sulfide (FeS), which is a dark-colored material that looks green mixed with the bright yellow yolk. Ferric sulfide (Fe2S3) is also sometimes claimed to be formed in this process, likely because it is itself a yellow-green substance. There is, however, less data to back this up, aside from the convenient color match. 

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