After a stint with Feyenoord, where he made no appearances, he returned to ADO where he experienced a breakout season, scoring 12 goals in 30 games which facilitated a move to Vitesse.
[2] He made his professional debut on 29 August 1999 as part of the ADO Den Haag first team in a home match against NAC Breda.
Coming on as a second-half substitute for Dennis Iliohan, he scored his first goal after only being on the pitch for one minute as ADO won 3–0.
[6] On 25 October, Kolk made his European debut in the UEFA Champions League group stage match against Lyon, coming on as a 68th-minute substitute for Jeffrey Talan in a 2–0 home loss.
[10] After returning from a loan at ADO, Kolk's chances of playing time improved after fellow forward Romano Denneboom was told to leave.
[11] This meant that Kolk was in the starting lineup against Spanish club Villarreal in the play-off round of the UEFA Cup on 26 August 2003.
[12] At Heerenveen, however, he clashed with head coach Foppe de Haan, which Kolk later admitted was due to his own "selfishness".
[4] On 15 October 2001, RKC Waalwijk agreed to loan Kolk for the remainder of the season in order for him to gain more playing time.
"[16] On 31 August 2005, Kolk was sent on a one-season loan to Zwolle, with Dominggus Lim-Duan making a move in the opposite direction to Excelsior.
[17] He had a highly successful season at the club, and finished as shared top scorer of the Eerste Divisie with 19 goals, alongside Berry Powel.
[20] He made 30 appearances during the 2006–07 season, in which he scored 12 goals as he could not heed the club from relegation, with ADO finishing bottom of the league.