Step 1
If you hold the card up to the light, you should be able to see the weird-looking symbols on the front and back of the card shine through, and join together in the word ‘POEM’.
Step 2
Googling all the previous solutions should give you the poem ‘I Wandered Lonely as a Cloud’ by William Wordsworth.
Alternative Hint
You should separate the letters into different groups based on their colour. The order in which to put the different groups is provided by the coloured numbers below the code of letters. Don’t be fooled by the order of the numbers, that is just the order of colour appearance. The only real information you get is a colour plus a number. Green is 4th, orange is 1st, blue is 5th, purple is 6th, yellow is 3rd and black is 2nd. Summing all that up, you should find IWAN DER EDLO NELY ASAC LOUD. You have found the poem ‘I wandered lonely as a cloud’ by William Wordsworth.
Step 3
The weird shapes on the back of the card next to the ‘Place Postage Here’ box are letters molten together. In the right order, they read CDEAB.
Step 4
Every letter on the front has one of the letters as well. The newspaper has the A, the letter from Kurt Vonnegut has the B, the letter from Fidel Castro has the C, the letter of Lt. Siegfried Sassoon has the D and the letter from Martin Luther King Jr. has the E. This information provides you with an order in which you should read the letters.
Step 5
You should count something in the poem, you will find out what later on!
Step 6 (2nd edition: added quote)
All the encircled words themselves can be found directly in the poem.
They have something else in common though. They have something else in common though. Like the quote says (in italics): everything around you is numbers. All the words have a reference to a number in their direct surroundings. Letter A has a French number before the word (solution is 4-1-9), letter B a proverb with a number around the word (solution is 20-3-22), letter C mentions a number directly after the word (solution is 9-4-3), letter D incorporates a number in the word next to the encircled one (solution is 1-6) and letter E places an anagram of a number after the word in red lining (solution is 3-1).
Step 7
The encircled word directs you to a line of the poem ‘I wandered lonely as a cloud’. The number that is being referred to next to the encircled word points you at the right letter from that line of the poem. ‘Bay 9’ gives you the M, and so on. If you work your way through all the numbers and words like this, you should find the following sequences per letter: A=ETO; B=YOU; C=MYS; D=AL; E=UT. Putting them in the correct order of CDEAB that gives us ‘MYSALUTETOYOU’, or in normal words ‘My salute to you’. The Final answer of the Final puzzle! Well done, and congratulations on finishing the Cards of Confound!