How to take the colour of a line plotted by an indicator and assign a number based on that colour (if colour X, -1 or if colour y, +1)?

Question

I have a small riddle that I can not manage to solve for a good while now!

It is possible to assign colours to values when coding a TV indicator but is it possible to do the opposite - to assign values to colours taken from an other indicator?

In other words, I have an indicator that plots a line and assigns colours to it (the colours can either be #2196f3 or #FF0000). What I would like to do is to have an other indicator below it taking the #colour value and plotting a new line based on that colour. For example if indicator A has turned from #2196f3 to #FF0000, the needed indicator B, changes from 1 to -1.

I have looked throughout the web to find a similar question with an answer but so far no luck ;( I am learning pine script so I apologize if its a silly question with an easy solution.

Thank you for you time!

Answer 1

We can use the == operator to check if a value is equal to something, rather than assigning it with just one = sign. *(I edited the original ema here to align with your indicator)We check the variables color and assign a number conditionally.

col1 = #2196f3 
col2 = #FF0000

bValue = css == col1 ? 1 : css  == col2 ? -1 : 0 

plot(bValue)

bullalert = bValue ==  1 and (bValue == -1)[1]
bearalert = bValue == -1 and (bValue ==  1)[1]

alertcondition(bullalert, title='Mod filter Bull', message='Mod filter Bull on {{interval}} chart. Price is {{close}}')
alertcondition(bearalert, title='Mod filter Bear', message='Mod filter Bear on {{interval}} chart. Price is {{close}}')

if our color variable is equal to one color, we assign 1, if the other color we assign -1, else it will be 0. We can then even go on to make an alert condition based on a positive or negative change in that number in reference to the bar prior.