Code completion menu looks awful on Blue Whale and Slate Gray themes

[Dian-Jiao]

Even though we can change it's colour in the settings, but we can't find the same color as the theme.
why not make the default colour as the theme colour?

[FMXExpress]

Can you provide steps to open the code completion?

[Dian-Jiao]

Can you provide steps to open the code completion?

For example

#include<queue>
using namespace std;
queue x<int>;
int main()
{
	x	//add a "." after the "x".
	return 0;
}