The finish or colour of your product is an important decision. If possilbe, try matching your light fittings and switches & sockets with the same finish. Matt white is the most popular downlight finish.
IP (International or Ingress Protection) defines a products level of resistance to dust and moisture. The first digit is for dust and the second digit is for moisture.
An IP65 rating offers a high resistance to moisture and is popular rating for outdoor lighting and electrical enclosures.
IP65 is usually specified for bathroom downlights but according to the Building Regulations, IP44 provides adequate protection for zones 1 & 2.