HI TB
This is a fascinating subject, I worked along with an historic painter or 2 in my time, One from Holland, and the other of English extract.

Red was a very common colour for paint, and for dying wool for cloth.

Red paint was formulated using a red iron oxide powder pigment mixed with linseed oil and white lead. The white lead now has been replaced with white powdered chalk, making it very enviromentally friendly.

The red colour for dying wool was formulated using cochineal a red bug from South America.

I have heard stories, and read accounts that the early settlers used the Thick fresh milk from newly calved cattle, as a basis for what was referred to as milk paint in which they mixed the red oxide powder.

Today of course the Barn red paint is readily available and mimiks the red paint of yeateryears gone by.

One thing that you will find is that the modern red paint will change rapidly back to its basic clours when exposed to the sun's rays, it will eventually change to an orange, and yellow.

I hope this helps

NH