Although this navy blue colour was used specifically for depicting the Union Flag on maritime flags on the basis of durability, it soon became standard on Union Flags, both on land and at sea. This navy blue colour trend was adopted for the Saltire itself by many flag manufacturers, resulting in a variety of shades of blue being depicted on the flag of Scotland ranging from "sky blue" to "royal blue" to "navy blue". Eventually, this situation resulted in calls to standardise the colour of Scotland's national flag. 