Finding those elusive parts to complete your monochrome minifig can be tricky. What follows is the method I use to see if I have the parts in my collection to complete a new colour.
A minifig consists of quite a few parts that will have to be found.
|B||Hips and Legs||970c00|
|C||Minifig, Head (Plain) – Blocked Open Stud||3626b|
|D||Minifig, Head (Plain) – Stud Recessed||3626c|
|E+F||Arm, (Matching Left and Right) Pair||981982|
The best tool I have found so far to determine what minifigs parts can be found in, is Bricklink. The above part numbers link to their corresponding pages on Bricklink. The torso assembly part numbers all start with 973c but vary due to different hand colours.
Two categories of parts exist that will have to be found, printed parts and unprinted parts. Unprinted parts are easier to find in a specific colour than printed parts and hands, to my knowledge have never been printed, so are a good place to start.
For this example we will use Bright Light Blue.
Using the link above for Hand – 983 will open the following Bricklink page.
Make sure the Color Info tab is selected.
The last column on the right is the Known Colors column.
Selecting Bright Light Blue brings up the following page.
This page shows that there are four known minifigs that have the Bright Light Blue hands. Having a spare one of these minifigs means the first parts for a Bright Light Blue monochrome fig. Otherwise going back to the Hands page, the first column on the left (Lots For Sale), contains the link that will show all sellers selling hands in Bright Light Blue.
Scrolling down and selecting the first link next to Bright Light Blue, the value in the Parts column, brings up the following page.
Selecting List with Images will make it a little easier to navigate.
Now there is a list with all the parts with Bright Light Blue as their base colour. The first item on the list is Arms and following the link will bring up the same page as the link above. This could be used as an alternative way to navigate through the parts.
The objective here, however is finding a torso. Going through the list, torsos can be found on page 3.
Selecting the link next to the torso will take you to the part page.
On the right of the page you will see the Item Appears In column.
Selecting Minifigs will bring up the page of minifigs this torso appears in.
Repeat until a useable torso is found.
And that is how I find the parts for my monofigs. Hope it helps.
Information correct as at 15 May 2017.