Just like much characters, Proto has a lot of forms, which can be different from Super to other ones.
Just like a lot of characters, Proto have a super form. His electricity and eyes became golden, his metal body becames white, his badge becames brick red and his coat becomes red (although Proto doesn't uses his coat too much on this form). Its good to note that Proto has a lot of difficult when using the Chaos Emeralds, and since he doesn't understands how the Emeralds work, he rarely turns Super or Hyper.
On this form, Proto's electricity glows all rainbow colors (mostly silver) and his coat, badge and metallic body is golden. He rarelly turns into this form because of his unknowledge with the Emeralds.
If his electricity fuses with Trick, they become the Neon Trickster. He can utilize both his and Trick's power, while both have control over this form.
On Sonic And The Dark Knight, Proto becomes a blacksmith and he sells various items that can make a certain status higher.
Also jokely known as "Rain Cloud" by Trick, if Proto absorbs too much electriciy, he might end up becoming uncontrolled, thus leaving his metal body and becoming a giant cloud of electric currents. On this form, his only weakness is fire, because water will just make him bigger and powerfull.
If Proto's systems get a virus or a dark force in it, his electricity will become red and glitched, thus becoming uncontrolled and accidentally using any attacks. Virused Proto can still be defeated by water or fire, however doing such will deactive both Proto itself and the Virus. Re-activing Proto after it will make him normal. However, this form is a rare occasion and only Mephiles was able to do it soo far.
A lot like Virus form, Proto's electricity will become red or black and start glitching if he is controlled by virus or dark force. He will do anything that it is re-programmed to do. Only Mephiles was able to control Proto soo far.
If deactivated, Proto's electricity will disappear, leaving only his "sleeping" metal body. The only way to deactivate him is by throwing a big amount of water or fire. He can be re-activated by installing high amount of electricity.