| Bile acids or steroidal conjugates can also cause purple discolouration. |
| She warned that sunbeds cause premature ageing of the skin resulting in loss of elasticity, sagging, wrinkling, freckling, yellowish discolouration and brown patches. |
| A little zinc in the mix will brighten the reds, and a little vanadium pentoxide is sometimes added to prevent discolouration. |
| Pollutants in the atmosphere and the attentions of birds and humans cause discolouration, encrustation and corrosion. |
| Herbert B. Berkeley recommended the use of sulphite of soda with pyrogallic acid to prevent discolouration of film. |
| Milking staff should look for clots, strings, wateriness or discolouration of milk. |
