Is it ok to use colour character in name (not surname character)?
Color character can be used in names. But be careful, a bad combination will ruin everything. I try to make up some. 

葉紅 is better than 葉紅魚. It evokes imagination of leaves turning red in the fall.

(It turned out that it's better if the name matches the surname.)

黃 itself is a surname, so I ve heard of few people's names with it.  I propose a name with it, however, for I like it very much.

懷黃 黃 means gold seal, a tally of official position. 佩紫懷黃是也。懷, hold. So 懷黃 means hold the gold seal, equivalent of take official position.

（懷 itself is a rare surname）

紫 is always a noble color. The uniforms of high rank officers in many dynasties are of 紫. 有言事金紫也。

You may think “佩紫” in “佩紫懷黃” is good （though here 紫 doesn't refer to the color of the uniform）, but it is  phonetically poor to many ears.

紓紫 has a close meaning as in 綰黃紓紫 and sounds good as well.

Unfortunately 綠 is usually the color of low rank officer's uniforms. But if we give good interpretation, it can also means a lot.

沈綠（chen3 lv4）

note：

沈 is not a surname here. For example, 方沈綠 is the full name.

沈 is a variant of 沉, but 沈 looks more poshԅ(¯ㅂ¯ԅ).

Interpretation:

沈綠：dark green. A comfortable, modest color.

Homonymic to 承（cheng3）綠，and 綠 is 籙's original character. So we can interpret it as 承籙.

圖籙，帝王承天命之書也。承籙 is one of the most ambitious, exaggerate words★.

Then 沈綠 is a superficially modest but actually exaggerate name. And if you explain all things to others you will receive awes for the cultural depth (and pretentiousness (don't care this part, COOL is more important than anything eles!))

There are many other colors, such as 朱/紅/緋/彤/丹/赭/茜/絳/栗/橘/翠/緗/蒼/青/皂/杏/漆/皓/黛/玄/ ……………………

As you may perceive, the examples I give are all about bureaucratic ambition but this is just one of the many topics of a name. So you are totally free of coming up with names of different styles with color characters in.

PS. My most self-content name that I propose is 李 嶔彧 (´▽｀)ノ♪

EDIT:

The poem 紅紅白白花臨水，碧碧黃黃麥際天 suddenly comes to my mind. And I think 際黃（Bordered by wheat fields） is a good choice. （Better with a surname of fourth tone, e.g. 宋際黃）