RJ45 Connections...

Pin Number Designations

There are pin number designations for each color in T-568B and T-568A.

                 T-568B                         T-568A
       --------------------------      ------------------------
Pin    Color             Pin Name      Color           Pin Name
---    -------------     --------      -------------   --------
 1     Orange Stripe     Tx+           Green Stripe    Rx+
 2     Orange            Tx-           Green           Rx-
 3     Green Stripe      Rx+           Orange Stripe   Tx+
 4     Blue              Not Used      Blue            Not Used
 5     Blue Stripe       Not Used      Blue Stripe     Not Used
 6     Green             Rx-           Orange          Tx-
 7     Brown Stripe      Not Used      Brown Stripe    Not Used
 8     Brown             Not Used      Brown           Not Used 

RJ45 Color-Coded Scheme

RJ45 cables have 8 color-coded wires, and the plugs have 8 pins and conductors. Eight wires are used as 4 pairs, each representing positive and negative polarity. The most commonly used wiring standard for 100baseT is T-586B stanrard described above. Prior to EIA 568A and 568B standards, the color-coded scheme was used to wire RJ45 cables. The table below depicts pin and color schemes used in traditional and standardized setup. 

Pin	Colored Scheme	T-568B (Common)	T-568A
1	Blue	Orange Stripe	Green Stripe
2	Orange	Orange	Green
3	Black	Green Stripe	Orange Stripe
4	Red	Blue	Blue
5	Green	Blue Stripe	Blue Stripe
6	Yellow	Green	Orange
7	Brown	Brown Stripe	Brown Stripe
8	White (or Grey)	Brown	Brown