Since about 90% of the vision impaired in Japan are said to have low visual capacity (hereafter referred to as "LVs"), Tactile Walking Surface Indicator's("TWSIs") visual recognizability has great significance. For color conspicuity, sufficient data on LVs is not yet collected, while the data on people with on vision impairment are ready. In order to study proper TWSI colors, based on scientific-evidence and independent from conventional wisdom, we created a system to measure the conspicuity focusing exclusively on colors. In conclusion the system's usability to measure color conspicuity for LVs was verified.