there are 2 things to consider , what kind of kernels frequently spawn , and what kind of gleam is the color you try to get.
the 1st thing is what kind of exos frequently spawn , in that regard i’d say that
turquoise, green , moss , yellow, mustard, orange , red, cherry , fuchsia, berry, violet,
maybe lilac as well are quite frequent colors, ofc there have been black and white exos as well but the ones i traveled to were a pain in the butt to get goo from (i normally get 5-15k kernels on an exo i like but on those i lost patience after 1k)
i dont know much about the exos in 2020 but for me considering exos since january there were only rare cases of blues/ cobalt/ cerulean/ azure/ white-black greyscales.
on the 2nd point i noticed a “hidden” rarity chart in block colors some years ago
differentiating between regular available block colors and gleambow only block colors.
now please note that this is entirely hypothetical and only experienced by my own testing and thoughts.
So i was testing if it was possible to mix gleambow gleam with regular available gleam to get lanterns of colors not available . i tested about 20-30 times at which ratio i would have a chance to get rare color. color me suprised that 1 regular gleam was enough to tip the scale of ruining the entire craft color of gleambowgleam and not once but at least 10 time and so i ruined every single testing craft i mean i was prepared for that to happen but still suprised, that gave me the theory of some hidden rarity so that players wouldnt be able to “multiply” gleambow gleam by refining with regular gleam mixed in . i continued testing with exo gleam and sometime mixed up to 4 colors together the result was every single time the regular available gleam got chosen.
And with the same mindset i was looking at my goo mutations. ofc sprays of gleambow only colors get sold fast and the starting goo matters as well but the mutation i get to the desired color are much less on that desired color if its on gleambow gleam.
a nice example is shadow blue , i tried to get tons of shadow blue with night azure goo
turns out i got tons of shadow cerulean even though night azure to shadow blue are only 2 mutation steps , but since shadow cerulean is a “regular” available color it all tended to go there
the prefered order by the system would be regular/sovereign > exo > gleambow
ofc that is hypothetical and i have no concrete data to proof it , just years long experience and what i kinda learned from it.