TAH-DAH! A list!
Robotoast!
ACCEPT: Move robots from the entrance (top) to the exit (bottom)!
Least parts: 3
Robocoffee!
If a robot's string starts with blue, accept. Otherwise, reject!
Least parts: 3
Robolamp!
ACCEPT: if there are three or more blues!
Least parts: 8
Robofish!
ACCEPT: if a robot contains NO red!
Least parts: 4
Robobugs!
ACCEPT: if the tape has only alternating colors!
Least parts: 11 (TheRandomPie_IV)
Robocats!
ACCEPT: if the tape ends with two blues!
Least parts: 11
Robobears!
ACCEPT: Strings that begin and end with the same color!
Least parts: 15 (flagitious)
RC Cars!
OUTPUT: The input, but with the first symbol at the end!
Least parts: 7
Robocars!
OUTPUT: Replace blue with green, and red with yellow!
Least parts: 7
Robostilts!
OUTPUT: Put a green at the beginning, and a yellow at the end!
Least parts: 9
Milidogs!
ACCEPT: With blue as 1 and red as 0, accept odd binary strings!
Least parts: 8
Soldiers!
OUTPUT: With blue as 1 and red as 0, multiply by 8!
Least parts: 7
Officers!
OUTPUT: With blue as 1 and red as 0, add 1 to the binary string!
Least parts: 18 (flagitious)
Generals!
OUTPUT: Subtract 1 from the binary string! (Input >= 1)
Least parts: 17 (flagitious)
Robotanks!
OUTPUT: With blue as 1 and red as 0, accept binary string > 15!
Least parts: 25 (TheRandomPie_IV)
Robospies!
OUTPUT: With blue as 1 and red as 0, accept natural powers of 4!
Least parts: 8
Androids!
ACCEPT: Some number of blue, then the same number of red!
Least parts: 12 (nitsuja)
Robochildren!
ACCEPT: An equal number of blue and red, in any order!
Least parts: 17 (nitsuja)
Police!
OUTPUT: Put a yellow in the middle of the (even-length) string!
Least parts: 32 (klmz)
Judiciary!
ACCEPT: (Even-length) strings that repeat midway through!
Least parts: 46 (klmz)
Teachers!
ACCEPT: X blue, then X red, then X more blue, for any X!
Least parts: 19 (flagitious)
Politicians!
ACCEPT: If there are exactly twice as many blues as red!
Least parts: 23 (Scepheo)
Academics!
OUTPUT: Reverse the input string!
Least parts: 25 (Pointless Boy)
Engineers!
ACCEPT: Perfectly symmetrical strings!
Least parts: 21 (nitsuja)
Roborockets!
OUTPUT: Swap blue for red, and red for blue!
Least parts: 7
Roboplanes!
OUTPUT: All of the blue, but none of the red!
Least parts: 7
Rocket Planes!
OUTPUT: The input, but with all blues moved to the front!
Least parts: 14 (klmz)
Robomecha!
OUTPUT: The input, but with the last symbol moved to the front!
Least parts: 19 (Pointless Boy)
Seraphim
ACCEPT: Two identical strings, separated by a green!
Least parts: 21 (Gunty)
Ophanim
ACCEPT: Read the tape as two numbers, A and B, split by a green: accept if A > B!
Least parts: 51 (TheRandomPie_IV)
Metatron
OUTPUT: Read the tape as two numbers, A and B, split by a green: output A + B!
Least parts: 84 (Nitrodon)