Comparison between different materials
ΔE
Comparison between different materials was performed by using the One Way ANOVA test, which revealed a significant difference between different groups after one day and after 14 days as Mean & standard deviation of color changes (ΔE after one day and after 14)

Means with the same superscript letters in the same column were insignificantly different as Means with different superscript letters in the same column were significantly different as 
Bar chart representing color changes (ΔE after 1 day and after 14 days) in all groups