On Gaia how do you combine the red bugs to make the red ink instead of getting 50 of each kind

If you go to Durem Depot and click on Exchange Bugs, it will automatically combine the bugs for you and tell you which inks you can make. If you are using different types of bugs and not 50 of the same one, once you click the ink it will ask you to tell how many of each and you will get to put in [for example] 25 of one type and 25 of another.