Those rolls of hay are called round bales.. The price varies depending on the kind of hay (grass or legume), its quality and on the supply/demand in the region where it's being sold.
Semi-permanent hair color has smaller molecules than temporary dyes. These dyes only partially penetrate the hair shaft. For this reason, the color will survive repeated washing, typically 4â5 shampoos or a few weeks.
This means that demi-permanent color can darken your hair color, but the absence of ammonia makes it unable to lighten the hair. Since it does not make a permanent color change, the color fades gradually, lasting up to 24 washes.