Yes, Definately. You can colour/foil/touch up your hair as normal, the manufacturers don't recommend lightening your extensions but going darker is fine.
They are applied using the latest Hair Friendly method of application, MicroRings or MicroBeads. These are Silicon lined aluminium rings/beads and non damaging to your natural hair.
Its not as easy to clean your scalp as thouroughly with beads/rings in, sometimes you may get a catch hair or two also which irritate the scalp, to help prevent possible itchies (build up of products /conditioner) purchase a scalp cleanser (contact me for recommended brands) from your local hairhouse warehouse/price attack salon.