yellow > white > light blue > darkblue/black
best way to learn how to read one of those is to head to a exo and look for lucent gems AFTER it has already been mined out that first day. (this is probably the best use of a mined out exo)
You are going to want to look for the yellow/white and light blue, if its dark blue it was there and has already been taken. if its black there isnt any of that resource there. go to the altitude of the lucent gem and pull up the atlas, if you look at the heat map for a lucent gem you can almost see the individual deposits, the dots on a atlas are about 10m. when you get close to a dot on the atlas start mining and when you find the deposit DONT mine it.
pull out the atlas in your off hand and look at the color, then imediately mine up that spot and then swap back to the atlas…
if you got everything it will tick to a darker color.
repeat this for about 2-3 hours and it will suddenly click and then you can apply it to anything else.
If you dont have access to a exo go to a public mine and repeat the same process but the mine has to be “used” and it has to have very little of the resources to learn how to properly read an atlas heatmap. otherwise its like trying to see a rain drop by looking at the clouds.
Alternatively if you can get to a exo with petroleum or primordial resin you can put that in the atlas and then look at that so you can see how far away the dots are from you. but i find you really learn it while mining.