Which question could be tested in a scientific manner?
what causes some people to be color-blind?
why should people be nice to other people?
why is the color purple better than the color red?
what are the best shoes to wear when exercising?

The questions from this lot which could be tested in a scientific manner would be "what causes some people to be color-blind"
and
"what are the best shoes to wear when exercising"
Both of these questions can be tested in a scientific way through an experiment. 

The scientific method is a series of steps followed by scientific investigators to answer specific questions about the natural world. it involves making observations, formulating a hypothesis, and conducting scientific experiments.the steps of the scientific method are •observation-the first step of the scientific method involves making an observation about something that interests you•question-once you've made your observation, you must formulate a question about what you have observed. •hypothesis-once you've made your observation, you must formulate a question about what you have observed. •experiment-once you've developed a hypothesis, you must design and conduct an experiment that will test it.•results-the results are where you report what happened in the experiment. •conclusion-the final step of the scientific method is developing a conclusion.i hope that this you : )

What's the yellow wallpaper?