Buh...but - the dark blue? The cyan? Ye gods, man, what did you do to the brown?
Some of those colors, I agree with - orange for example. God, yes, please, but I use the dark blue, dark grey, and like the color of the cyan for cave moss. I can barely see a worthwhile color difference between Gold and Yellow, too, and those colors are really too similar to be separate when we have such a limited availability of slots, in my opinion.
EDIT: Also, Dark Sea Green? Eh. Not a fan. Such are my thoughts on this matter.
Hm, first of all, I would really like to figure out a good color to use for luminescence. That would, I think, merit 1 color of its own. Let me know if you have one, for luminescent things like that moss.
However, there will always be casualties when large changes are made. That's why I said I should have thought of it at the start. Now, I was thinking dark greys would migrate to either slate or a different color, to give more hues to stone. You may be right on the gold. It seemed natural to include it because gold is such a special metal. Dark sea green was intended to be used to give some stone a jade-like color.
Also, turns out you can't change colors completely arbitrarily due to hard-coded materials and things (thanks Japa for pointing it out, I did forget). Here's a rethought version with some hints of what the game may/will/should, depending on whether it's moddable or not, use those for. Here if you want "gray" as in metallic you are supposed to go for gray90, and if you want a dark, calm, stone-like color you should choose a tint (slateg, rosequartz, burlywood).
=== Current ===
{| style="margin: 0 auto; border-spacing: 0"
|-
| style="vertical-align: top; padding: 0" |
{| style="text-align: center; border-spacing: 0 1px; margin: 0 auto; background: black; border-left: 1px solid black; border-right: 1px solid black"
|- style="background: #fff"
! style="padding: 0.15em 0.4em; width: 3em" | Col.
! style="padding: 0.15em 0.4em; width: 3em" | Bri.
! style="padding: 0.15em 0.4em; width: 9em" | Name
|- style="color: white; background: {{fgcolor|0:0}}"
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | Black
|- style="color: white; background: {{fgcolor|1:0}}"
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | Blue
|- style="color: white; background: {{fgcolor|2:0}}"
| style="padding: 0.15em 0.4em" | 2
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | Green
|- style="color: white; background: {{fgcolor|3:0}}"
| style="padding: 0.15em 0.4em" | 3
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | Cyan
|- style="color: white; background: {{fgcolor|4:0}}"
| style="padding: 0.15em 0.4em" | 4
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | Red
|- style="color: white; background: {{fgcolor|5:0}}"
| style="padding: 0.15em 0.4em" | 5
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | Magenta
|- style="color: white; background: {{fgcolor|6:0}}"
| style="padding: 0.15em 0.4em" | 6
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | Brown
|- style="color: black; background: {{fgcolor|7:0}}"
| style="padding: 0.15em 0.4em" | 7
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | Light grey
|}
| style="vertical-align: top; padding: 0" |
{| style="text-align: center; border-spacing: 0 1px; margin: 0 auto; background: black; border-left: 1px solid black; border-right: 1px solid black"
|- style="background: #fff"
! style="padding: 0.15em 0.4em; width: 3em" | Col.
! style="padding: 0.15em 0.4em; width: 3em" | Bri.
! style="padding: 0.15em 0.4em; width: 9em" | Name
|- style="color: white; background: {{fgcolor|0:1}}"
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | Dark grey
|- style="color: black; background: {{fgcolor|1:1}}"
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | Light blue
|- style="color: black; background: {{fgcolor|2:1}}"
| style="padding: 0.15em 0.4em" | 2
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | Light green
|- style="color: black; background: {{fgcolor|3:1}}"
| style="padding: 0.15em 0.4em" | 3
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | Light cyan
|- style="color: black; background: {{fgcolor|4:1}}"
| style="padding: 0.15em 0.4em" | 4
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | Light red
|- style="color: black; background: {{fgcolor|5:1}}"
| style="padding: 0.15em 0.4em" | 5
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | Light magenta
|- style="color: black; background: {{fgcolor|6:1}}"
| style="padding: 0.15em 0.4em" | 6
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | Yellow
|- style="color: black; background: {{fgcolor|7:1}}"
| style="padding: 0.15em 0.4em" | 7
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | White
|}
|}
=== Proposed ===
{| style="margin: 0 auto; border-spacing: 0"
|-
| style="vertical-align: top; padding: 0" |
{| style="text-align: center; border-spacing: 0 1px; margin: 0 auto; background: black; border-left: 1px solid black; border-right: 1px solid black"
|- style="background: #fff"
! style="padding: 0.15em 0.4em; width: 3em" | Col.
! style="padding: 0.15em 0.4em; width: 3em" | Bri.
! style="padding: 0.15em 0.4em; width: 9em" | Name
|- style="color: white; background: {{fgcolor|0:0}}"
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | Black
|- style="color: white; background: #006994"
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | Sea (water down)
|- style="color: white; background: #228b22"
| style="padding: 0.15em 0.4em" | 2
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | ForestGreen
|- style="color: white; background: #6c7b8b"
| style="padding: 0.15em 0.4em" | 3
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | SlateG4 (night,sky)
|- style="color: white; background: #cd0000"
| style="padding: 0.15em 0.4em" | 4
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | Red2 (magma down)
|- style="color: white; background: #8b008b"
| style="padding: 0.15em 0.4em" | 5
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | Magenta4 (noble)
|- style="color: white; background: #8b7355"
| style="padding: 0.15em 0.4em" | 6
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | BurlyWood4 (brown)
|- style="color: white; background: #AA98A9"
| style="padding: 0.15em 0.4em" | 7
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em; text-align: left" | RoseQuartz
|}
| style="vertical-align: top; padding: 0" |
{| style="text-align: center; border-spacing: 0 1px; margin: 0 auto; background: black; border-left: 1px solid black; border-right: 1px solid black"
|- style="background: #fff"
! style="padding: 0.15em 0.4em; width: 3em" | Col.
! style="padding: 0.15em 0.4em; width: 3em" | Bri.
! style="padding: 0.15em 0.4em; width: 9em" | Name
|- style="color: black; background: #e5e5e5"
| style="padding: 0.15em 0.4em" | 0
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | Metal (gray90)
|- style="color: black; background: #45C3B8"
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | Turquoise (water)
|- style="color: black; background: #7cfc00"
| style="padding: 0.15em 0.4em" | 2
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | LawnGreen
|- style="color: black; background: #b9d3ee"
| style="padding: 0.15em 0.4em" | 3
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | SlateGray (ice wall)
|- style="color: black; background: #FFA000"
| style="padding: 0.15em 0.4em" | 4
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | OrangeP (magma)
|- style="color: black; background: #f5deb3"
| style="padding: 0.15em 0.4em" | 5
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | Wheat
|- style="color: black; background: #ffd700"
| style="padding: 0.15em 0.4em" | 6
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | Gold1
|- style="color: black; background: {{fgcolor|7:1}}"
| style="padding: 0.15em 0.4em" | 7
| style="padding: 0.15em 0.4em" | 1
| style="padding: 0.15em 0.4em; text-align: left" | White
I have a feeling the idea of making magma on your level orange and water on your level turquoise may cause a lot of controversy, but it's a matter of what you're used to.
Feels a little neutered this way. Well, again, thoughts - just an idea for now.