▁market , ▁the ▁Eric of on ▁was ▁available ▁in ▁ 1 8 ▁colors , ▁but ▁after ▁transfer ▁of ▁production ▁to ▁North ▁Electric , ▁the ▁number ▁of ▁colors ▁was ▁reduced ▁to ▁eight . ▁A ▁small ▁number ▁of ▁ph ones ▁with ▁clear ▁and ▁met all ic ▁finish es ▁were ▁produced ▁for ▁special ▁prom ot ions . ▁The ▁most ▁popular ▁and ▁widely ▁produced ▁colors ▁were ▁bright ▁red ▁and ▁bright ▁white . ▁Other ▁colors ▁included ▁various ▁past el ▁sh ades ▁of ▁blue , ▁green , ▁and ▁p ink . ▁The ▁phone ▁was ▁never ▁produced ▁in ▁black . ▁ ▁Eric ot one ▁Most ▁Eric of ons ▁had ▁mechanical ▁rot ary ▁d ial s , ▁typical ▁of ▁all ▁ph ones ▁made ▁in ▁the ▁era . ▁ ▁While ▁Eric of ons ▁produced ▁by ▁Eric sson ▁used ▁mini ature ▁bu zz ers ▁as ▁ring ers , ▁North ▁Electric ▁introduced ▁the ▁electronic ▁" Er ic ot one " ▁r inger . ▁ ▁The ▁Eric ot one ▁r inger ▁used ▁a ▁simple , ▁one - trans istor ▁oscill ator ▁circuit ▁to ▁produce ▁a ▁distinct ive ▁" ch ir ping " ▁sound . ▁ ▁This ▁was ▁one ▁of ▁the ▁earliest ▁uses ▁of ▁a ▁trans istor ▁in ▁a ▁tele phone ; ▁tele ph ones ▁with ▁mechanical ▁bell ▁ring ers ▁and ▁rot ary ▁d ial s ▁did ▁not ▁need ▁trans ist ors . ▁ ▁Touch - t one ▁North ▁Electric ▁introduced ▁a ▁touch - t one ▁version ▁of ▁the ▁Eric of on ▁in ▁the ▁United ▁States ▁in ▁ 1 9 6 7 . ▁Production ▁of ▁this