colour filling worktop joint with gap

It will depend on the gap size but for small imperfections less than 2mm it should work, over that size I would look to silicon the gap to water seal then cut back the top to then apply colourfil to blend away.

Colourful is a joint adhesive which will fill minor imperfections anything bigger than 0.5mm is not a minor imperfection.

All depends on the joint. If it not flat = no Too wide = no It need to be minimal gap or chip to get away with colour fill.

Hi it will all depends on size of gab and if the two surfaces are level with each other

Colourfill is used when you have mitred your worktops and are ready to tighten the 3 bolts that should be recessed underneath, once tightened the excess is removed and carefully cleaned with the alcohol supplied. If these are new worktops and the joints aren't perfectly tight then they still need scribed to the walls, if this is to fix existing worktops it's quite ineffective as it will shrink into the gap and need redone all the time, if it's because the mitres water damaged, next to a sink, and you just want to stop it getting any worse then you should use a coloured silicone but any worktop without a perfect mitre will eventually be damaged and need replacing. I use clear silicone on my mitres to make them waterproof, I only use colourfill if asked to fix a chip or a scratch.