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If you want another color, open a color of your choosing
and drag and drop the texture into the
"\assets\minecraft\textures\block" folder.
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Make sure to backup the color if you want to change the color again.

Default textures are in the "Default Textures" folder if you want 
the regular textures. This includes the MCMETA file for magma.
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Make sure to also include the MCMETA file for some colors.
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