Which of the following is a good guideline to follow when planning colour in bar graphs?

A) Use blue to convey reliability.
B) When you design black-and-white graphs,use stripes,wavy lines,and checks to indicate different segments or items.
C) Avoid glossy paper.
D) Use different colours for different bars when they have different meanings.

Using different colours for different bars in a bar graph is a good guideline to follow when planning colour, especially when the bars have different meanings. This helps to make the graph easier to read and understand. Using blue to convey reliability (option A) is not a widely accepted guideline and may not be applicable to all cases. Option B is specific to black-and-white graphs and may not be applicable to coloured graphs. Option C is not related to planning colour in bar graphs.