Likely fallout and/or oversight from https://github.com/ShivamPandya/wordle/pull/9. Turning letters yellow wasn't working correctly in cases when the first repeated letter occured in the guess before its first occurrence in the correct answer and when the second occurrence in the guess was placed correctly. E.g. when guessing "LABEL" when the correct answer was "SKILL"

When evaluating a guess and assigning colours to letters, deal with green letters first and check against them when turning letters yellow. This is to prevent situations when a repeated letter in a guess gets turned yellow because the same letter is already green elsewhere in the word.

Resolves: https://github.com/ShivamPandya/wordle/issues/8

When letters of guesses are printed in yellow, it should indicate that the solution contains the letter in question at a different position which hasn't been correctly guessed yet. If a letter is printed in yellow and the same letter is already green at a different position, the yellow letter should indicate that this letter also appears elsewhere in the solution, at a position other than the green letter and other than the yellow letter.

Below, the second (yellow) 'E' on line 2 correctly indicates that there is another 'E' in the word, other than the green one at the second position:

In the next screenshot, the second and third 'S' in "Swiss" (both yellow) would mean that there are two more 'S's in the solution, other than the green one at the first position, meaning the solution starts with "SSS". This is not the case, of course. Both yellow 'S's in fact refer, quite unhelpfully, to the green 'S' at the first position:

The next screenshot illustrates an impossible situation. The second 'E' in "SWEET" is yellow, which should indicate that there is an 'E' somewhere in the solution which hasn't been guessed yet. However, all other letters have already been guessed. The yellow 'E' refers to the green 'E' next to it. The second 'E' should be white.

Note: I don't know what the official rules of Wordle are, if indeed there are any. What I assume here to be the "correct" behaviour is based on the behaviour of https://www.nytimes.com/games/wordle/index.html and two other Wordle websites I tested a long time ago and whose URLs I've since forgotten.