Visible light communication has been considered one of promising candidate technology to solve performance limitation due to bandwidth shortage at radio frequency (RF) band. In VLC system, the visible light is used not only for illuminating rooms but also for an optical data transmission. ACO-OFDM is a power efficient modification of OFDM to use in VLC systems. Wireless communication systems generally require estimating and tracking the fading channel in order to detect transmitted data coherently. In this work, spline interpolation based channel estimations for comb type pilot distribution is proposed over visible light channels. Computer simulation results have confirmed that the proposed channel estimation technique has a clear BER performance advantages compared with linear interpolation based channel estimation for higher order modulations.