Blockly’s default category colors

[Max Stephen Russell]

It’s the most natural and tempting thing in the world to come up with attractive color palettes for one’s own app, but in this unique block environment I am reluctant to throw out Blockly’s investment in colour vision accommodation. This might eliminate some visual pop and zing, but it seems like a good solid tradeoff to me if I withhold my usual innovativeness from fiddling around with colors that I think “work” and just accept the default palette. Any comments?

“Blockly provides several themes in an effort to accommodate some types of colour vision deficiency.“

https://developers.google.com/blockly/guides/create-custom-blocks/block-colour

-Steve

Max Stephen Russell

[Christopher Allen]

Hi Max,

It’s the most natural and tempting thing in the world to come up with attractive color palettes for one’s own app, but in this unique block environment I am reluctant to throw out Blockly’s investment in colour vision accommodation. This might eliminate some visual pop and zing, but it seems like a good solid tradeoff to me if I withhold my usual innovativeness from fiddling around with colors that I think “work” and just accept the default palette. Any comments?

“Blockly provides several themes in an effort to accommodate some types of colour vision deficiency.“

It's worth being aware that the themes we provide only specify colours for the default categories (i.e., the categories of the blocks that we provide in the library of block definitions loaded by import 'blockly/blocks', and so if you are creating additional categories of blocks you will need to choose additional colours for your own categories, which might in turn cause you to reconsider the colours for the default categories.

This is one of the main reasons why we are planning to deprecate Blockly's theme system (and instead support setting per-category colours via CSS)—though we will still provide in our documentation lists of the actual colour values for each of the existing themes, since we believe they are fairly well chosen.

Very broadly I would suggest that if you want to pick your own colours—including ones for additional categories, if you are using one of our themes—that you do some reading about best practices in the use of colour in user interfaces, consult with someone who has expertise in visual accessibility, and/or use a colour blindness simulator to evaluate your colour choices.

Best wishes,

Christopher

[Max Stephen Russell]

Christopher, thank you for the excellent education on this subject. Very helpful.  -Steve