I want to ask confirmation regarding Japanese colors. I understand that there are NOUN, and I-adj version of some colors. Such as 赤＆赤い, 青＆青い, etc.
But this part below is something I cannot confirm. Some article say that it is okay to say both "車は赤です" and "車は赤いです", but some say that you can only say "車は赤です". Which one is correct?
Also about basic colors. It seems that green (緑) and purple (紫) don't have i-adj version. But how about yellow (黄色), brown (茶色), orange (橙色) & grey (灰色)? Do they have i-adj version? I'm pretty sure I've heard 黄色い and 茶色い, but wasn't sure about 橙色い and 灰色い...
Update for specific reference I read about:
This sentence is copied from Link:
"It might be possible to use 赤いです [akai desu] in simple sentences, but I know that 赤です [aka desu] is always safe."
And this one is copied from Link:
"ボールはしろです. The ball is white. When using primary colors to modify a noun, use the i-adjective form; otherwise, use the no-adjective form."