cubicweb #13500378 improve a bit the captcha readability [validation pending]

some day we will have a better implementation of this captcha generator, but meanwhile, we should trick a bit the color ranges to increase redability

prioritynormal
typeenhancement
done in3.20.16
load left0.000
closed by#5149a4d4cf54 [captcha] improve a bit the redability of generated captcha images (closes #13500378)
patch[captcha] improve a bit the redability of generated captcha images (closes #13500378) [applied]
attachment