The aim of this study was focusing on the excipients interaction especially between coloring agents and diluents. There were two coloring agents with different charges ; methylene blue(M) showing positive charge while amaranth(A) giving negative charge but all having same concentration of 0.1% w/w in each mixing batch. There are five types of starch using as diluents; arrowroot starch (W), rice starch (R), cassava starch (S), corn starch (C) and lesser yam starch (l). The physical properties of starch powder and paste (5%w/v) were evaluated as angle of repose and viscosity respectively. While the concentration of both coloring agents were determined by either UV spectroscopy or eye observation. The storage conditions of all samples were kept in both light and dark area for 7 weeks. It was found in powder form that C gave the most stable of M while R gave the worst for m in both light and dark condition. M showed less influences on flow properties of starches than a in a powder state. The flow of C with M gave the best results. The W paste was shown to be the most stable physical properties. M was suitable for S paste in a dark condition. While A was suitable for C, R and W paste in a light condition. The charges of coloring agents might not be a major influence on some physical properties of starch in both powder and paste form.