You can now order 3 of the PCBs from OSHPark for $4.90!:

https://oshpark.com/shared_projects/IvtIc9f2

The bill of materials is as follows:

Part Value         Device        Package     Description                   
C1   0.1uF Ceramic C-EUC0805     C0805       CAPACITOR, EU symbol    
C2   22uF Tantalum C-EUC0805     C0805       CAPACITOR, EU symbol    
JP1  2.54mm        PINHD-1X2     1X02        PIN HEADER                    
JP2  2.54mm        PINHD-1X3     1X03        PIN HEADER                    
JP3  2.54mm        PINHD-1X2     1X02        PIN HEADER                    
LED1 GM5WA94310A   GM5WA94310A   GM5WA94310A Chip LED RGB                  
R1   Blue LED      R-EU_R0805    R0805       RESISTOR, EU symbol     
R2   Red LED       R-EU_R0805    R0805       RESISTOR, EU symbol     
R3   Green LED     R-EU_R0805    R0805       RESISTOR, EU symbol     
R4   10K           R-EU_R0805    R0805       RESISTOR, EU symbol     
R5   100Ohm        R-EU_R0805    R0805       RESISTOR, EU symbol     
S1   SKHMPSE010    TACT Switch   SKHMPXE010  6.2X6.5mm 
ESP  ESP8266       ESP8266       ESP-03      ESP8266 Wifi module  
U1   MIC5209-3.3YS MIC5209-3.3YS SOT223      LDO REGULATOR

You will need to pick R1,2,3 to suit the LED you order as this can change. Please see the datasheet of the LED when ordering. The power supply is 3.3V.

With the MIC5209-3.3YS regulator you can have an input voltage of 3.3V to 16V and it has reverse input voltage protection (the regulator shuts off safely)!

Update:

It turns out the GM5WA94310A LED is obselete, as is the SKHMPSE010. Suitable replacements for these are:

Osram Opto LRTB GFTM - http://docs-europe.electrocomponents.com/webdocs/0e24/0900766b80e2426e.pdf

APEM DTSM644RV - http://docs-europe.electrocomponents.com/webdocs/0642/0900766b80642d5a.pdf

If using the Osram Opto, appropriate resistors are (note the designations have changed too):

R1   Red  LED      R-EU_R0805    R0805       RESISTOR, EU symbol, 47ohm     
R2   Green LED     R-EU_R0805    R0805       RESISTOR, EU symbol, 6.8ohm     
R3   Blue LED      R-EU_R0805    R0805       RESISTOR, EU symbol, 22ohms