When you get a Sovereign Planet, you can chose the colours you want via the World Control Beacon. You can also change these colours to any of the available/unlocked colours once every pay cycle (every month I believe).
When you choose a colour, the block type changes colour instantly (pretty much instantly) so you can see the colour before you finalise the changes. Whilst you are in this stage (pre-finalising the colours) you are not able to harvest the block. You’ll see the “This worlds block colours have not been finalised via the World Controller”.
Reason for post:
However, if you Transform Chisel the block, you will then be able to harvest the block. Tried this with multiple types of blocks, some of them need to be Transform Chiselled more than once before you can harvest (grass seeds). But you can just transform chisel multiple times to get back to the original block type.
This is obviously not a via option for mass collection of blocks, albeit a possible option But this could be useful if someone wants a block of each colour to display for some reason - maybe someone is making a museum of all unlocked colours? I have used this to test different colour combination for the floors in my shop, for example.
Whilst the blocks are in the pre-finalised stage, you can still harvest the ‘hidden drops’ such as Pulsating Orbs from Sponge and Earthyams from Soil.