Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Type of sign | Shape | Border | Background colour | Text/Symbol |
| --- | --- | --- | --- | --- |
| Warning | Triangular | Red | Yellow | Black |
| Prohibition | Circular | Red | Yellow | Black |
| Mandatory instructions | Circular | White | Blue | White |
| Supplementary | Rectangular | White Red | Blue Yellow | White Black |
| Directions, sometimes | Rectangular | Black | Yellow | Black |
| Information | Rectangular | White | Blue | White |
Question:
Which color is the background of the mandatory instructions?
Answer:
Blue