Two Bollinger Bands indicators, accomplices, linked together one into the other. One drawn, the other not drawn but coloring the first one.
The role of indicator No. 2, the one with the smallest standard deviation, is, in fact, to define a neutral zone. If one leaves it, a buy or a sell position is suggested. By playing on the period and the standard deviation of n°2, we increase or shrink the neutral zone, we lengthen
or shrink the colored zones of the first.

// G.G. le 29 octobre 2023

/* Deux indicateurs Bollinger Bands, complices, enchassés
l'un dans l'autre. L'un dessiné, l'autre non dessiné mais
colorant le premier.
Le rôle de l'indicateur n°2, celui avec le plus petit
écart-type est, en fait, de définir une zone neutre.
Si l'on en sort, une prise de position à l'achat ou à la vente
est suggérée.
En jouant sur la période et l'écart-type du n°2, on augmmente
ou on rétrécit la zone neutre, on allonge ou on rétrécit les
zones colorées du premier.

Two Bollinger Bands indicators, accomplices, linked together
one into the other. One drawn, the other not drawn but
coloring the first one.
The role of indicator No. 2, the one with the smallest
standard deviation, is, in fact, to define a neutral zone.
If one leaves it, a buy or a sell position is suggested.
By playing on the period and the standard deviation
of n°2, we increase or shrink the neutral zone, we lengthen
or shrink the colored zones of the first.

*/

// Bollinger Enveloppe
MoyEnv = Average[perEnv](close)
ETypeEnv = STD[perEnv](close)
ligneSup = MoyEnv + nbStdEnv * ETypeEnv
ligneInf = MoyEnv - nbStdEnv * ETypeEnv

// Bollinger Signal
MoySig = Average[perSig](close)
ETypeSig = STD[perSig](close)
BBupSig = MoySig + nbStdSig * ETypeSig
BBdwnSig = MoySig - nbStdSig * ETypeSig

// Close à l'extérieur BB signal ???
If (close >= BBupSig) then
FracBolLog = 1
endif
If (close < BBupSig) and (close > BBdwnSig) then
FracBolLog = 0
endif
If (close <= BBdwnSig) then
FracBolLog = -1
endif

//Coloration de l'enveloppe
If FracBolLog = 1 then
r = 0
g = 127
b = 255
alpha = 110
endif
// bleu / rouge = impossible
If FracBolLog = 0 then
r = 0
g = 0
b = 0
alpha = 0
endif

// blanc / bleu
If FracBolLog = -1 then
r = 255
g = 0
b = 227
alpha = 90
endif

COLORBETWEEN(ligneSup, ligneInf,r,g,b,alpha)

return ligneSup as "Bande Sup Env", ligneInf as "Bande Inf Env"