Answer:
Your breath becoming visible on a cold day and bleaching your hair have one thing in common: they both involve a process called condensation. Condensation is when a gas changes into a liquid because of cooling or losing energy.
When you exhale on a cold day, the water vapor in your breath comes in contact with the cold air outside and forms tiny water and ice droplets, which collectively appear as a thick cloud of breath. This is similar to how fog is formed when moist air cools off.
When you bleach your hair, you use a mixture of hydrogen peroxide and bleach powder to strip the natural pigment from your hair strands. This mixture also opens the hair cuticle, which allows water molecules to escape from the hair shaft. As the water molecules leave the hair, they cool down and condense into liquid water on the surface of the hair. This makes the hair wet and also more porous, which means it can absorb more color or toner afterwards.