The colored dots do not represent any slot.

It can be a little tricky to solve, but it only requires an application of logic. I start with all white. If I get any dots, then I will keep that many whites in my next guess (all slotted at the beginning of the sequence.) I will replace the remaining with grey. The next step is a little more complicated...okay, quite a bit more complicated.
Here is an example:
First round: One green | Second round: One green, one orange
What the first round tells you is that you have one WHITE stone in the right place, but you have no way of knowing which one.
You set up your next guess as WHITE, GREY, GREY, GREY.
The grading for the second round tells you that you have one WHITE and one GREY stone in your lineup and both are in the 2nd, 3rd, or 4th position. (This is because if WHITE was in the correct position there would be nowhere for the incorrectly placed GREY stone to go. If WHITE isn't in the correct position, then one of the GREY stones must already be in the correct position.)

Note that if you are graded with 2 green, then you know WHITE is 1st and GREY is in one of the three remaining spots. If you are graded with 2 orange, then you know GREY must be in the 1st position (as there is nowhere else for it to go,) and WHITE must be in one of the three remaining positions.

A game will be filled with several dozen of these little eliminations.