Blue dye or red dye?

re

I’ve been taking blue, but I heard one is easier to read?..

The last test I took was on the 5th, and it was (almost certain) negative... but it was also a blue lined 5 days before one.

Should I test again with red dye?

Or because it didn’t show up then, it probably will still be negative?

** I haven’t had any symptoms for my period or a pregnancy.