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*-----------------------------------------------------------*
| .. .. . | . . .. | .. 5 . |
| . . 5. | . .5. .5. | ... . . |
| 5.. .. . | 5. . . | .... . .. |
|-------------------+-------------------+-------------------|
| . . . | . . . | . . 5 |
| . . . | 5. 5. . | . . . |
| . 5 . | . . . | .. . .. |
|-------------------+-------------------+-------------------|
| . . . | . . . | 5 . . |
| . . 5. | . .5 . | . . .. |
| 5. . 5.. | . . .5 | . . .. |
*-----------------------------------------------------------*
Okay, this is not multi-coloring, it is just going to be two color coloring. Pick a candidate which appears in at least one group that has exactly two candidates in it. Let's start with r9c6. We will color it +.
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*-----------------------------------------------------------*
| .. .. . | . . .. | .. 5 . |
| . . 5. | . .5. .5. | ... . . |
| 5.. .. . | 5. . . | .... . .. |
|-------------------+-------------------+-------------------|
| . . . | . . . | . . 5 |
| . . . | 5. 5. . | . . . |
| . 5 . | . . . | .. . .. |
|-------------------+-------------------+-------------------|
| . . . | . . . | 5 . . |
| . . 5. | . .5 . | . . .. |
| 5. . 5.. | . . .5+ | . . .. |
*-----------------------------------------------------------*
Now we are going to color with a '-' any candidates which, all by themselves, share a group with only one previously colored '+' candidate. Here, r2c6 is the only other candidate in column 6, and r8c5 is the only other candidate in box 8, so color those candidates '-'.
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*-----------------------------------------------------------*
| .. .. . | . . .. | .. 5 . |
| . . 5. | . .5. .5- | ... . . |
| 5.. .. . | 5. . . | .... . .. |
|-------------------+-------------------+-------------------|
| . . . | . . . | . . 5 |
| . . . | 5. 5. . | . . . |
| . 5 . | . . . | .. . .. |
|-------------------+-------------------+-------------------|
| . . . | . . . | 5 . . |
| . . 5. | . .5- . | . . .. |
| 5. . 5.. | . . .5+ | . . .. |
*-----------------------------------------------------------*
Now we are going to color with a '+' any candidates which, all by themselves, share a group with only one previously colored '-' candidate. Here, r8c3 is the only other candidate in row 8, so color it '+'.
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*-----------------------------------------------------------*
| .. .. . | . . .. | .. 5 . |
| . . 5. | . .5. .5- | ... . . |
| 5.. .. . | 5. . . | .... . .. |
|-------------------+-------------------+-------------------|
| . . . | . . . | . . 5 |
| . . . | 5. 5. . | . . . |
| . 5 . | . . . | .. . .. |
|-------------------+-------------------+-------------------|
| . . . | . . . | 5 . . |
| . . 5+ | . .5- . | . . .. |
| 5. . 5.. | . . .5+ | . . .. |
*-----------------------------------------------------------*
At this point there are no more conjugate pairings that can be made off of this starting point. Now it is time to see if any deductions can be made. We know that either the +'s are true and the -'s are false, or the +'s are false and the -'s are true.
If two +'s or -'s showed up in the same group then we could assign false to that color. But that is not the case here.
Instead, what we have is a candidate cell which sees both a + and a -.
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*-----------------------------------------------------------*
| .. .. . | . . .. | .. 5 . |
| . . *5* | . .5. .5- | ... . . |
| 5.. .. . | 5. . . | .... . .. |
|-------------------+-------------------+-------------------|
| . . . | . . . | . . 5 |
| . . . | 5. 5. . | . . . |
| . 5 . | . . . | .. . .. |
|-------------------+-------------------+-------------------|
| . . . | . . . | 5 . . |
| . . 5+ | . .5- . | . . .. |
| 5. . 5.. | . . .5+ | . . .. |
*-----------------------------------------------------------*
Cell r2c3 can see a '-' along row 2, and can see a '+' along column 3. Since either '-' or '+' must be true, there is no way that the 5 in r2c3 can be true, thus we can remove it as a candidate. Then its just simple sudoku....r2c3 <> 5 => r3c1 = 5 => r3c4 & r9c1 <> 5 => r5c4 = 5 => r5c5 <> 5.
If there were no deductions, then you could try a different, uncolored, start point.