 
 <prompt> Wetin be di UK spelling of one popular colour? Based on di question wey dey above, write one context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: Grey-box testing (American spelling: gray-box testing) involve say you must sabi internal data structures and algorithms make you fit design tests, but as you dey execute those tests for the user level, or black-box level. The person wey dey test no need full access to the software's source code. Manipulating input data and formatting output no dey qualify as grey-box, because the input and output dey clearly outside of the "black box" wey we dey call the system wey dey under test. This difference dey very important especially when you dey do integration testing between two modules of code wey two different developers write, where only the interfaces dey exposed for test. 