Blue is a lucky colour in South Korea and is a suitable colour for a gift or for wrapping paper. More money should be given if you have a warm or significant relationship with the person getting married or with the person who invited you. Do not give money that has a denomination of four, eg. It is always useful to cultivate a network of Korean contacts for such introductions. Often Korean business people's comprehension of English is not as sound as their courtesy would lead you to believe.
Korean negotiations tend to be lengthy and protracted.
It is not advisable to appear pushy during a discussion. If a sensitive issue arises on which agreement is not forthcoming, leave it for discussion at a later meeting, preferably through a Korean intermediary. In Korea, the human relationship which exists between the parties to a contract is more important than the legal document itself. Relationships will often be developed after hours, at pubs and restaurants over copious quantities of food and alcohol. Such gatherings are usually seen as male-only affairs and are regarded as highly important by your Korean counterparts.